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LINUX INTERVIEW QUESTIONS
1} what is inode?
All UNIX files have its description stored in a structure called inode.
The inode contains info about the file-size, its location, time of last
access, time of last modification, permission and so on. irectories are
also represented as files and have an associated inode.
2} what are the process states in UNIX?
As a process e!ecutes it chan"es state accordin" to its circumstances.
Uni! processes have the follo#in" states$%unnin"$ The process is either runnin" or it is read& to run . 'aitin"$
The process is #aitin" for an event or for a resource. (topped$ The
process has been stopped, usuall& b& receivin" a si"nal. )ombie$ The
processes are dead but have not been removed from the process table.
3} what command should you use to check the number o
iles and disk space used and each users deined !uotas?
rep*uota
"} what command is used to remo#e the password assi$ned
to a $roup?
"pass#d +r
%} what can you type at a command line to determine which
shell you are usin$?
echo (//
&} write a command to ind all o the iles which ha#e been
accessed within the last 3' days(
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find 0 -t&pe f -atime -12 3 filename.t!t
)} what is a *ombie?
)ombie is a process state #hen the child dies before the parent
process. In this case the structural information of the process is still in
the process table.
)} what daemon is responsible or trackin$ e#ents on your
system?
s&slo"d
+} what do you mean a ,ile -ystem?
4ile (&stem is a method to store and or"anize files and directories on
dis5. A file s&stem can have 6 different formats called file s&stem t&pes.
These formats determine ho# the information is stored as files and
directories.
78 tell me the name of director& structure hierarch& for /inu!
0root 0boot 0bin 0sbin 0proc 0mnt 0usr 0var 0lib 0etc 0dev 0opt 0srv
0tmp 0media
1'} what does .boot directory contains?
The 0boot0 director& contains static files re*uired to boot the s&stem,
such as the /inu! 5ernel, boot loader confi"uration files. These files
are essential for the s&stem to boot properl&.
11} i someone deletes .boot directory rom your ser#er/
than what will happen?
In that case &our server #ill be in unbootable state. 9our (erver cant
boot #ithout 0boot director& because this director& contains all
bootable files
12} what does .de# directory contain?
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The 0dev director& contains all device files that are attached to s&stem
or virtual device files that are provided b& the 5ernel.
13} what is the role o ude# daemon?
The udev demon used to create and remove all these device nodes or
files in 0dev0 director&.
1"} what kind o iles or nodes .de#. directory contains and
how do I access or see de#ice iles?
:loc5 evice 4iles$-
:loc5 device files tal5s to devices bloc5 b& bloc5 ;< bloc5 at a time = ?
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0dev0psau!
1&} tell me the name o de#ice ile or parallel port
0rinters(
0dev0lp2
1)} what does .etc.X11. directory contains?
The 0etc0X
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of the Oournal used to maintain consistenc&. The default Oournal size
ta5es about a second to recover, dependin" on the speed of the
hard#are.
21} 4ny idea about et" ile system?
The e!tJ or fourth e!tended files&stem is a Oournalin" file s&stem
developed as the successor to e!t1. !tJ files&stem released as a
functionall& complete and stable files&stem in /inu! #ith 5ernel
version 6.K.6.
4eatures of e!tJ file s&stem$-
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m5e6fs -t e!tJ 0dev0L
2%} 7plain .proc ilesystem?
0proc is a virtual files&stem that provides detailed information about
/inu! 5ernel, hard#ares and runnin" processes. 4iles under 0proc
director& named as Lirtual files. :ecause 0proc contains virtual files
thats #h& it is called virtual file s&stem. These virtual files have uni*ue
*ualities. Eost of them are listed as zero b&tes in size. Lirtual files
such as 0proc0interrupts, 0proc0meminfo, 0proc0mounts, and
0proc0partitions provide an up-to-the-moment "limpse of the s&stems
hard#are. Dthers, li5e the 0proc0files&stems file and the 0proc0s&s0
director& provide s&stem confi"uration information and interfaces.2&} 6an we chan$e iles parameters placed under .proc
directory?
9es To chan"e the value of a virtual file, use the echo command and a
"reater than s&mbol =3 to redirect the ne# value to the file. 4or
e!ample, to chan"e the hostname on the fl&, t&pe$
echo http$00###.ne!tstepJit.com3 0proc0s&s05ernel0hostname
2)} 8hat is the use o sysctl command?
The 0sbin0s&sctl command is used to vie#, set, and automate 5ernel
settin"s in the 0proc0s&s0 director&.
2+} .proc. directory contains a number o directories with
numerical names( 8hat is that?
These directories are called process directories, as the& are named
after a pro"rams process I and contain information specific to that
process.
29} 8hat is :4I;?
%AI, stands for %edundant Arra& of Ine!pensive is5s. %AI is a
method b& #hich same data or information is spread across several
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dis5s, usin" techni*ues such as dis5 stripin" =%AI /evel 2, dis5
mirrorin" =%AI /evel
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%AI /evel < is based on Eirrorin" techni*ue. /evel < provides
redundanc& b& #ritin" identical data to each member dis5 of the arra&.
The stora"e capacit& of the level < arra& is e*ual to the capacit& of one
of the mirrored hard dis5s in a ard#are %AI or one of the mirroredpartitions in a (oft#are %AI. %AI < provides redundanc& means
"ood protection a"ainst dis5 failure. In %AI < #rite speed is slo# but
read speed is "ood.
3"} 7plain :4I; %?
%AI /evel ? is based on rotatin" parit& #ith stripin" techni*ue.
%AI-? stores parit& information but not redundant data =but parit&
information can be used to reconstruct data. The stora"e capacit& of(oft#are %AI level ? is e*ual to the capacit& of the member
partitions, minus the size of one of the partitions if the& are of e*ual
size. The performance of %AI ? is based on parit& calculation process
but #ith modern CUs that usuall& is not a ver& bi" problem. In %AI
? read and #rite speeds are "ood.
M
3%} 8hich kernel module is re!uired or -otware:4I;?RmdS module
3&} which utility or command is used or creatin$ sotware
:4I;sor :57
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pieces of the stripe on each dis5 The pieces a stripe is bro5en into are
called chun5s.To "et "ood performance &ou must have a reasonable
chun5 size.
4or bi" I0Ds #e re*uired small chun5s and for small I0Ds #e re*uiredbi" chun5s.
39} 8hat is -840 -pace?
(#ap space in /inu! is used #hen the amount of ph&sical memor&
=%AE is full. If the s&stem needs more memor& resources and the
%AE is full, inactive pa"es in memor& are moved to the s#ap space.
'hile s#ap space can help machines #ith a small amount of %AE, it
should not be considered a replacement for more %AE. (#ap space islocated on hard drives, #hich have a slo#er access time than ph&sical
memor&.
"'} 8hat are the steps to create -840 iles or 0artition?+
Create s#ap partition or file + 'rite special si"nature usin" Rm5s#apS
+ Activate s#ap space b& Rs#apon +aS command + Add s#ap entr&
into 0etc0fstab file
"1} 5ow you will create swap ile o si*e " => and eplainswap ileentry in .etc.stab ile?
Use RddS command to create s#ap file.
dd if>0dev0zero of>0('A4I/ bs>J
m5s#ap 0('A4I/
s#apon +a
ntr& into 0etc0fstab file.0('A4I/ s#ap s#ap defaults 2 2
"2} ell me the steps to remo#e the swap ile?
4irstl& disable the s#ap file b& Rs#apoffS command. %emove (#ap file
entr& from 0etc0fstab file. No# remove the s#ap file b& RrmS
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command.
"3} 8hat can we do with @partedA command or utility?+
Lie# the e!istin" partition table + Add partitions from free space or
additional hard drives + Chan"e the size of e!istin" partitionsJJ8 o# #e #ill chec5 free space on drive 0dev0sda #ith parted
command Fparted 0dev0sda
"%} 6an we resi*e the si*e o a partition?
9es, #e can resize the size of partition b& RpartedS command.
Fparted 0dev0sda
printTo resize the partition, use the resize command follo#ed b& the minor
number for the partition, the startin" place in me"ab&tes, and the end
place in me"ab&tes. 4or e!ample$
resize 1
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Fv"create L/2 0dev0sda6 + Create lo"ical volume from volume
"roup b& RlvcreateS command.
Flvcreate -/
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%"} 5ow you will check on Dour ser#er or system de#iceE
mapper is installed or not?
Chec5 the follo#in" file. Fcat 0proc0misc
if this file contains Rdevice-mapperS term it means device mapper is
installed on &our s&stem.
%%} 5ow are snapshots in
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umount 0dev0Qv"name30Qlvname3
and then use the lvremove command$
lvremove 0dev0Qv"name30Qlvname3
&1} 8hich command is used to create
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CU( stands for RCommon UNIX rintin" (&stemS. CU( is a open
source printin" s&stem developed b& Apple Inc. CU( uses the
Internet rintin" rotocol =I to allo# local printin" and print
sharin".&&} 8hat is the location o lo$ iles or 6U0-?
The lo" files for the CU( printin" s&stem are located in the
0var0lo"0cups0 director&.
&)} 8hat is DUC?
9UE stands for 9ello# do" Updater, Eodified because it is based on
9U, the 9ello# do" Updater. 'here does the name 9ello# do" comefrom 9ello# o" is a version of /inu! for the o#er Architecture
hard#are and is %E-based, Oust li5e %ed at nterprise /inu! and
4edora. 9U, and later 9UE, #ere #ritten b& the /inu! communit& as
a #a& to maintain an %E-based s&stem.
K8 'hat are the advanta"es of 9UE
+ Automatic resolution of soft#are dependencies. + Eultiple soft#are
locations at one time. + Abilit& to specif& particular soft#are versionsor architectures.
&9} 5ow you will install sotware by DUC?
&um install Qp5"name3
)'} 8hich option is re!uired to assume the answer @yesA to
any !uestions asked durin$ installation o packa$e
dependencies or DUC?
The R-&S option is used to assume the ans#er R&esS.
4or !ample
&um -& install s*uid
)1} 5ow to remo#e a sotware by DUC?
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&um remove Qp5"name3
)2} 5ow Cany :un
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Intel EKJT
iaKJ IntelZ Itanium
ppc 16-bit I:EZ D'%, I:E e(erver\ p(eriesZ, and I:E e(erver
i(eriess172! KJ-bit I:E e(erver (&stem z
)%} 5ow to install
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it *ueries the %E database for #hich pac5a"e o#ns Qfilename3.
'hen specif&in" a file, specif& the absolute path of the file.
+2} 5ow to #eriy all installed packa$es?
rpm +La
+3} 5ow to #eriy the si$nature o an rpm?
rpm -@ test-0home 0home e!t1 acl < 6
No# remount 0home partition #ith acl option.
mount -t e!t1 -o acl 0dev0sda1 0home
++} 5ow to Biew 46
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setfacl +remove-all Qfile-name3
9'} 8hat is the dierence between pop3 and imap
protocols?
D1 =ost Dffice rotocol is the most commonl& used internet
mail protocol.It#or5s on
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F pass#d Qusername3 -l
This mi"ht be useful in the situation #here &ou dont #ant to
permanentl& remove the user, but &ou Oust #ant it disabled and no
lon"er able to use the s&stem. The user #ill still receive emails fore!ample, but he #ill not be able to lo"in and chec5 them out.
To re-enable the account ,Oust use belo# command
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repeatedl& ,
at command is used to schedule the tas5 onl& once i.e to run onl& one
time.
9%} 8hat is network bondin$ in noneDN:DDT>&es
%eplace above I address #ith &our actual I address. (ave file and
e!it to shell prompt.
(tep F6$ Eodif& eth2 and eth< confi" files$
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Dpen both confi"uration usin" vi te!t editor and ma5e sure file read as
follo#s for eth2 interface F vi 0etc0s&sconfi"0net#or5-scripts0ifcf"-
eth2 Eodif&0append directive as follo#s$ LIC>eth2
U(%CT/>no DN:DDT>&es EA(T%>bond2 (/AL>&es:DDT%DTD>none
Dpen eth< confi"uration file usin" vi te!t editor$
F vi 0etc0s&sconfi"0net#or5-scripts0ifcf"-etheth< U(%CT/>no DN:DDT>&es EA(T%>bond2
(/AL>&es :DDT%DTD>none
(ave file and e!it to shell prompt.
(tep F 1$ /oad bond driver0module
Ea5e sure bondin" module is loaded #hen the channel-bondin"
interface =bond2 is brou"ht up. 9ou need to modif& 5ernel modules
confi"uration file$
F vi 0etc0modprobe.conf Append follo#in" t#o lines$
alias bond2 bondin" options bond2 mode>balance-alb miimon>
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ermanent ' addr$ 22$2c$67$cK$be$?7
(lave Interface$ ethlock in
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(tatus
Information about other metadata structures
If this information lost, &ou are in trouble =data loss so /inu!
maintains multiple redundant copies of thesuperbloc5 in ever& files&stem. This is ver& important in man& emer"enc& situation, for
e!ample &ou can usebac5up copies to restore dama"ed primar& super
bloc5.
4ollo#in" command displa&s primar& and bac5up superbloc5 location
on 0dev0sda1$
F dumpe6fs 0dev0hda1 Y "rep -i superbloc5
J K 8hat is the load a#era$e o the ser#er and 8hat is an
acceptable -er#er
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1'&} 6an we ha#e two apache ser#ers ha#in$ di #ersions?
9es, &ou can have t#o different apache servers on one server, but the&
cant listen to the same port at the same time.Normall& apache listens
to port 2 #hich is the default TT port. The second apache version
should listen to another port #ith the /isten option in httpd.conf, for
e!ample to port
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N,- -7:B7:
1} 7plain this entry .shared
192(1&+(1('.2%%(2%%(2%%('sync/rw
allo#s all s&stems #ith
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N4( stands for Net#or5 4ile (&stem. N4( #as ori"inall& developed b&
(un Eicros&stems in the
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The e!portfs command is used to maintain the current table of
e!ported file s&stems for N4(.
1"} 7plain command @.usr.sbin.eports EA?
It #ill flush ever&thin" out of the 5ernels e!port table. An& clients that
are active #ill "et ne# entries added b& mountd #hen the& ma5e their
ne!t re*uest.
1%} 8hich option is used with eports command to display
the current eport list/ also displays the list o eport
options?
e!portfs -v
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2'} 8hat do you understand by @nsstat Eo all E23"A
command?
It #ill (ho# all information about all versions of N4(.
21} 8hat do you understand by @nsstat Kns Kser#er E3A
command?
It #ill sho# statistics for N4( version 1 server.
22} 6an N,- share mounted on 8indow X0 and Mustiy your
answer?
No, 'indo# X operatin" s&stem doesnt support nfs protocol.
23} 192(1&+(1(%1J.data is eported by N,- -er#er and i want
to add this N,- share to client .etc.stab ile( 5ow you will
add this entry in .etc.stab ile?
F device mount-point fs-t&pe options dump fsc5order
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2&} 8hat is @portmapA?
The portmapper 5eeps a list of #hat services are runnin" on #hat
ports. This list is used b& a connectin" machine to see #hat ports it
#ants to tal5 to access certain services.2)} 5ow you will check @portmapA ser#ice is runnin$ or not?
rpcinfo -p
2+} I am unable to mount a N,- share( 5ow will you trace
out the reason?
4irstl&, chec5 that &ou have permissions to mount nfs share or not.
Chec5 0etc0e!ports file.
(econdl& &ou can "et %C error$ ro"ram Not %e"istered =or anotherR%CS error
4or this chec5 &our N4( server and portmap service runnin" or not b&
Rrpcinfo -pS
29} 6an I modiy eport permissions without needin$ to
remount clients in order to ha#e them take eect?
9es. The safest thin" to do is edit 0etc0e!ports and run Re!portfs -rS.
,0 -7:B7:
1} 5ow to deny speciic users access to the ,0 ser#er?
To den& specific users access to the 4T server, add their usernames to
the 0etc0vsftpd0 ftpusers file. :& default, s&stem users such as root and
nobod& are included in this list.
2} 6an we create lo$s or tp authenticated sessions?
9es, If the !ferlo"[enable directive in vsftpd.conf is set to 9(, file
transfers usin" the 4T protocol are lo""ed to 0var0lo"0!ferlo".
Information such as a time stamp, I address of the client, the file
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bein" transferred, and the username of the person #ho authenticated
the connection is included in the lo" entr&.
3} 8hat is meanin$ o maLclients parameter?
Ea!imum number of clients that can connect at one time. If set to 2,
the number of clients is unlimited.
"} Gn which port B-,0 ser#er works ?
4T uses t#o ports, 62 and 6
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%ed at nterprise /inu! ? or 4D%A includes the vsftpd 4T
service.
vsftpd-6.2.?-
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'hen enabled, vsftpd attempts to maintain lo"in sessions for each
user throu"h lu""able Authentication Eodules =AE.
3} Is there any way to monitor clients connected to
#stpd?9es. 'e actuall& have t#o sli"htl& different methods to
monitor vsftpd clients. 4irst, ma5e sure &ou have enabled the confi"
option, Rsetproctitle[enable>9(S li5e in our e!ample above and
restart &our vsftpd server. Then run the command R#atch ps -Cvsftpd
-o user, pid, stime, cmdS to #atch the processes includin" ip,
username and actions li5e idle or data retrieval.
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:IN uses 0etc0named.conf as its main confi"uration file, the
0etc0rndc.conf file as the confi"uration file for name server control
utilit& rndc, and the 0var0named0 director& for zone files and the li5e.
2} 8hat is >IN;?
:IN stands for :er5ele& Internet Name omain #hich is the most
commonl& used omain Name (&stem =N( server on the Internet.
3} Gn which #ersion o bind u ha#e worked?
:IN 7
"} 8hat is the role o ;N-?
A N( server, or name server, is used to resolve an I address to a
hostname or vice versa.
%} Gn which port ;N- ser#er works?
N( servers use port ?1 b& default. Incomin" and out"oin" pac5ets
should be allo#ed on port ?1. Also allo# connections on port 76< if&ou confi"ure a li"ht#ei"ht resolver server. The N( control utilit&,
rndc, connects to the N( server #ith TC port 7?1 b& default. If &ou
are runnin" rndc on the name server, connections on this TC port
from localhost should be allo#ed. If &ou are runnin" rndc on
additional s&stems, allo# connections to port 7?1 =or #hatever port
&ou have chosen to confi"ure from these additional s&stems.
&} 8hat is round robin ;N-?
%ound robin N( is usuall& used for balancin" the load of
"eo"raphicall& distributed 'eb servers. 4or e!ample, a compan& has
one domain name and three identical home pa"es residin" on three
servers #ith three different I addresses. 'hen one user accesses the
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home pa"e it #ill be sent to the first I address. The second user #ho
accesses the home pa"e #ill be sent to the ne!t I address, and the
third user #ill be sent to the third I address. In each case, once the I
address is "iven out, it "oes to the end of the list. The fourth user,therefore, #ill be sent to the first I address, and so forth.
)} 8hat is Name -er#er?
A name server 5eeps information for the translation of domain names
to I addresses and I addresses to domain names. The name server is
a pro"ram that performs the translation at the re*uest of a resolver or
another name server.
+} 8hat is 0rimary name ser#er or primary master ser#er?
rimar& name server0primar& master is the main data source for the
zone. It is the authoritative server for the zone. This server ac*uires
data about its zone from databases saved on a local dis5. The primar&
server must be published as an authoritative name server for the
domain in the (DA resource record, #hile the primar& master server
does not need to be published.
9}8hat is -econdary name ser#er.sla#e name ser#er?
(econdar& name server0slave name server ac*uires data about the
zone b& cop&in" the data from the primar& name server =respectivel&
from the master server at re"ular time intervals. It ma5es no sense to
edit these databases on the secondar& name servers, althou"h the& are
saved on the local server dis5 because the& #ill be re#ritten durin"
further cop&in".
1'} what is :oot name ser#er?
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%oot name server is an authoritative name server for the root domain
=for the dot. ach root name server is a primar& server, #hich
differentiates it from other name servers.
11} what is -tealth name ser#er?
(tealth name server is a secret server. This t&pe of name server is not
published anhere. It is onl& 5no#n to the servers that have its I
address staticall& listed in their confi"uration. It is an authoritative
server. It ac*uires the data for the zone #ith the help of a zone
transfer. It can be the main server for the zone. (tealth servers can be
used as a local bac5up if the local servers are unavailable.
I12} 8hat do you mean by @:esource :ecordsA?
Information on domain names and their I addresses, as #ell as all
the other information distributed via N( is stored in the memor& of
name servers as %esource %ecords =%%.
13} 7plain @
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There is al#a&s onl& one (DA record in the file, and it is placed at the
be"innin" of the file of authoritative resource records.
1&} what is @4 :ecordA?
A =Address records assi"n I addresses to domain names of
computers. The I address cannot have a dot at the end.
1)} 7plain @6N4C7 :ecordA?
(&non&ms to domain names can be created usin" CNAE records.
This is often referred to as creatin" aliases for computer names.
1+} 8hat are @5IN,G and X :ecordsA?
IN4D and TXT records are for information onl&. An IN4D record
has t#o items in its data part. The first item is information about
hard#are, and the second one is information about soft#are. A TXT
record contains a "eneral data strin" in its data part.
!ample $ test.com IN (DA ^ ^ mail IN A
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2'} 7plain @0: :ecordsA?
A ointer %ecord =T% is used to translate an I address into a
domain name.
6
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-U port 4 ser#er ypes ?
+ rimar& omain Controller =C + :ac5up omain Controller
=:C + A( omain Controller
K8 'hich protocol (AE:A server uses (E:, #hich stands for (erver
Eessa"e :loc5, is a protocol for sharin" files, printers, serial ports,and communications abstractions such as named pipes and mail slots
bet#een computers.
)} 5ow ;oes a 8orkstation ind its ;omain 6ontroller?
There are t#o different mechanisms to locate a domain controller$ one
method is used #hen Net:ID( over TC0I is enabled and the other
#hen it has been disabled in the TC0I net#or5 confi"uration.'here Net:ID( over TC0I is disabled, all name resolution involves
the use of N(, broadcast messa"in" over U, as #ell as Active
irector& communication technolo"ies.
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+} 6an -amba >e a >ackup ;omain 6ontroller to an N"
0;6?
No. The native NTJ (AE replication protocols have not &et been full&
implemented.
9} 5ow ;o I :eplicate the smbpasswd ,ile?
%eplication of the smbpass#d file is sensitive. It has to be done
#henever chan"es to the (AE are made. ver& users pass#ord
chan"e is done in the smbpass#d file and has to be replicated to the
:C. (o replicatin" the smbpass#d file ver& often isnecessar&.As the
smbpass#d file contains plainte!t pass#ord e*uivalents, it must not
be sent unencr&pted over the #ire. The best #a& to set up smbpass#d
replication from the C to the :C is to use the utilit& rs&nc. rs&nc
can use ssh as a transport. ssh itself can be set up to accept onl& rs&nc
transfer #ithout re*uirin" the user to t&pe a pass#ord.As said a fe#
times before, use of this method is bro5en and a#ed. Eachine trust
accounts #ill "o out of s&nc, resultin" in a bro5en domain. This
method is not recommended. Tr& usin" /A instead.1'} 6an -amba ully replace my 8indows N ser#er that is
not a 0rimary ;omain 6ontroller 0;6?
(amba can completel& serve files and printers to 'indo#s, Oust as a
'indo#s NT server #ould.
11} 6an -amba replaces my 8indows N 0;6?
Not completel&. (amba domain control capabilities for a 'indo#s 7!
client are solid and complete, and so these clients #ould probabl&
never 5no# the difference. The domain control support for 'indo#s
NT06222 clients is still bein" developed. Currentl&, enou"h has been
implemented to allo# a 'indo#s NT client to Ooin a (amba-controlled
domain, but there is more to domain control than that. The most
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conspicuous absence is the lac5 of support for 'indo#s NT trust
relationships and the (AE replication protocol used bet#een NT Cs
and :ac5up omain Controllers =:Cs.
12} 8hat 60 and U;0 ports re!uired or Net>IG- o#er
60.I0 use?
The N:T name service uses port
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share, the client is issued a tree connection I =TI. The TI is used
in all re*uests to access files contained in the resource to #hich the
TI refers. In this #a& (E: protocol #or5s.
1"} 5ow man sections samba coni$uration ile smb(con
contains?
smb.conf file contains three sections.
user1)} 5ow you will #eriy that your smb(con ile doesnt ha#e
any mistakes and misspellin$s?
Rtestparm S tool that verifies the s&nta! of a confi"uration
file=smb.conf.
testparm -s smb.conf
1+} 8hat is the use o @smbclientA command?
RsmbclientS is used to displa& the list of shares on &our server. This
verifies that smbd is runnin" and functionin" correctl&. The -/ option
instructs smbclient to enumerate the shares on the server rather than
actuall& connectin" to one. The -N s#itch instructs smbclient to use an
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anon&mous lo"in rather than the lo"in name of the current user.
smbclient -/ localhost -N
Antother use of RsmbclientS command to connect the samba share.
smbclient 00Qserver30Qshare3 -U Qusername3
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The most li5el& cause is that ('AT is not listenin" to connections, or
&ou have used the #ron" U%/ in tr&in" to connect to ('AT. ('AT
usuall& lives behind port 72
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It #ill define the "roup id to be used for all file access in the place of
the users primar& "roup.
(ubmitted :&$-Larun mail-I$ -5umar.varun
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domain trust relationships. This is impossible #ith server-level
securit&. The second reason is that, under server-level securit&, each
smbd process must 5eep an open connection #ith the authentication
server. This can drain a 'indo#s NT C *uic5l&. Under domain-level securit&, this connection is maintained onl& lon" enou"h to
perform the validation, thus conservin" valuable resources. The final
reason is that, as a domain member, the (amba server has access to
much more information about user accounts, #hich can be used to
automate the creation and deletion of user accounts upon demand.
33} what is nmbd daemon?
This daemon handles all name re"istration and resolution re*uests. It
is the primar& vehicle involved in net#or5 bro#sin". It handles all
U-based protocols. The nmbd daemon should be the first command
started as part of the (amba startup process.
3"} 8hat is smdb daemon?
This daemon handles all TC0I-based connection services for file-
and print-based operations. It also mana"es local authentication. It
should be started immediatel& follo#in" the startup of nmbd.
3%} 8hat is winbindd daemon?
This daemon should be started #hen (amba is a member of a
'indo#s NTJ or A( domain. It is also needed #hen (amba has trust
relationships #ith another domain. The #inbindd daemon #ill chec5
the smb.conf file for the presence of the idmap uid and idmap "id
parameters. If the& are found, #inbindd #ill use the values specified
for UI and I allocation. If these parameters are not specified,
#inbindd #ill start but it #ill not be able to allocate UIs or Is.
3&} 7plain the parameter @wins support O DesA used
in smb(con?
If the (amba server #as confi"ured to provide 'IN( support =R#ins
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support > 9esS, then the 'IN( server is able to provide name
resolution for all of the hosts that are not listed in the 0etc0hosts file or
#ithin the N(. Ea5in" this adOustment in the Name (ervice (#itch
confi"uration file =0etc0nss#itch.conf allo#s the /inu! s&stem to*uer& the 'IN( server for local name resolution. This saves manual
adOustments to host files.
3)} 5ow to automate -C> share mountin$ durin$ system
startup?
Add smb share entr& in 0etc0fstab file.
00I[A%(([D4[(%L%0(hared 0shared smbfs noauto,defaults
2 2
3+} how to start and stop samba ser#er?
0etc0init.d0smb restart
-7NC4I< -7:B7:
1} 5ow to start sendmail ser#er ?
service sendmail restart2} Gn which ports sendmail and senmail with --< works ?
:& default, (endmail uses TC and U port 6? for non-encr&pted
transfers. If the (endmail server is confi"ured to use ((/ for
encr&ptin" email sent and received, it uses port JK?.
3} 7plain use o @trustedEusersA ile ?
/ist of users that can send email as other users #ithout a #arnin"
includin" s&stem users such as apache for the Apache TT (erver.
"} 7plain the use o @localEhostEnamesA ile ?
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If the email server should be 5no#n b& different hostnames, list the
host- names in this file, one line per hostname. An& email sent to
addresses at these hostnames is treated as local mail. The
4ATU%=_use[c#[file` option must be enabled inthesendmail.mc file for this file to be referenced.
%} eplain the use o .etc.aliases ile ?
0etc0aliases, can be used to redirect email from one user to another. :&
default, it includes redirects for s&stem accounts to the root user. It
can then be used to redirect all email for the root user to the user
account for the s&stem administrator.
&} 6an we use --< 7ncryption with -endmail ?
9es, (endmail can be confi"ured to encr&pt email sent and received
usin" ((/ =secure soc5ets la&er.
)} 8hat is -endmail?
(endmail is an ETA, meanin" it accepts email messa"es sent to it
usin" the (ET proto- col and transports them to another ETA email
server until the messa"es reach their destinations. It also acceptsemail for the local net#or5 and delivers them to local mail spools, one
for each user.
+} 8hat is the role o CU49} 8hich are the important
coni$uration iles or -endmail ser#er??
An EUA =Eail User A"ent #ith access to the mailbo! file, directl& or
throu"h a net#or5 file
s&stem, can read messa"es from the dis5 and displa& them for the
user. This is "enerall& a console or #ebmail application runnin" on the
server.
The 0etc0mail0 director& contains all the (endmail confi"uration files,
#ithsendmail.cf and submit.cf bein" the main confi"uration files.
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The sendmail.cf file includes options for the mail transmission a"ent
and accepts (ET connections for sendin" email. The submit.cf file
confi"ures the mail submission pro"ram.
1'} 5ow to coni$ure sendmail to accept mail or local
deli#ery that is addressed to other hosts?
Create a 0etc0mail0local-host-names file. ut into that file the
hostnames and domain names for #hich sendmail should accept mail
for local deliver&. nter the names #ith one hostname or domain
name per line. And also ma5e sure that (endmail confi"uration file
should contain Ruse[c#[fileS option.
dnl /oad class ># #ith other names for the local host4ATU%=_use[c#[file
11} 8hen an or$ani*ation stores aliases on an
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the desired aliases, rebuild the aliases database file #ith the
ne#aliases command.
13} Dou ha#e been asked to create a sendmail coni$uration
that sends all local mail to a mail hub/ while directly
deli#erin$ mail addressed to eternal systems(
Create a sendmail confi"uration containin" the EAI/[U: define to
identif& the mail rela& host for local mail. Use the /DCA/[U(%
command to e!empt the root users mail from rela&in".
dnl efine a rela& server for local mail define=_EAI/[U:,
_smtp.test.com dnl Users #hose mail is not passed to the mail hub/DCA/[U(%=root
%ebuild and reinstall sendmail.cf, and then restart sendmail.
1"} 5ow to coni$ure multiple mail !ueues?
m5dir 0var0spool0m*ueue0*ueue.< m5dir
0var0spool0m*ueue0*ueue.6 m5dir 0var0spool0m*ueue0*ueue.1
chmod M22 0var0spool0m*ueue0*ueue.< chmod M22
0var0spool0m*ueue0*ueue.6 chmod M22 0var0spool0m*ueue0*ueue.1
Add the UU[I% define to the sendmail confi"uration to use the
ne# *ueue directories.
dnl eclare the *ueue director& path define=_UU[I%,
_0var0spool0m*ueue0*ueue.G
1%} 5ow to disable certain -C0 commands?
Add the conf%ILAC9[4/A( define to the sendmail confi"uration toset rivac& Dptions that disable un#anted, optional (ET commands.
ere #e #ill disables the XN, L%49, L%:, and T%N commands.
dnl isable XN, L%49, L%: and T%N
define=_conf%ILAC9[4/A(, _noe!pn,novrf&,noverb,noetrn
%ebuild and reinstall sendmail.cf, and then restart sendmail.
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1&} In which -endmail coni$uration ile we ha#e to make
chan$es?
#e #ill ma5e the chan"es onl& in the sendmail.mc file, and the
chan"es #ill be moved into the sendmail.cf file for us.
1)} 8hen -endmail dispatches your email/ it places the
ser#ers hostname behind your username/ which becomes
the @rom addressA in the email ie(
userPmail(test(com(>ut we want to use the domain name
and not the hostname?
define=_confDEAIN[NAE,
_test.comdnl 4ATU%=_rela&[entire[domaindnl
1+} 8hat does .etc.mail.access ile contains?
The access database =R0etc0mail0accessS is a list of I addresses and
domainnames of allo#able connections.
4ATU%=_access[db,_hash -TQTE43 -o 0etc0mail0access.dbdnl
and cat 0etc0mail0access
localhost.localdomain %/A9 localhost %/A9
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21} 8hich anti#irus you ha#e inte$rated with sendmail ?
ClaimAL
22} 8hat is 6lama#ECilter?
Clamav-Eilter is a tool to inte"rate sendmail and clamAL antivirus.
23} 8hich coni$uration iles are re!uired to inte$rate
sendmail and 6laim4B anti#irus?
milter.conf and clamav-milter
2"} 5ow to test sendmail inte$ration with 6laim4B?
"rep Eilter 0var0lo"0maillo"9ou have to "et follo#in" t&pe of messa"es.
sendmail$ Eilter add$ header$ X-Lirus-(canned$ ClamAL version
2..6, clamav-milter version 2..6 on mail.test.com sendmail$
Eilter add$ header$ X-Lirus-(tatus$ Clean
2%} 8hich tool you ha#e used to block spammin$?
(pamAssassin
2&} 8hat does @.etc.mail.A directory contains?
The 0etc0mail0 director& contain all the (endmail confi"uration files,
#ithsendmail.cf and submit.cf bein" the main confi"uration files.
2)} 7plain the use o .etc.mail.relayEdomains ile?
The 0etc0mail0rela&-domains file is used to determine domains from
#hich it #ill rela& mail. The contents of the rela&-domains file should
be limited to those domains that can be trusted not to ori"inate spam.
2+} 8hat is the name o spamassassin coni$uration ile?
0etc0mail0spamassassin0local.cf
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29} 5ow to check mail ueue o sendmail?
0usr0lib0sendmail -bp
or
mail*3'} 5ow to use m" macro processor to $enerate a
new sendmail(c?
mJ 0etc0mail0sendmail.mc 3 0etc0mail0sendmail.cf
C4I< -7:B7:
1} 8hich !mail process use @concurrecylocalA control ile?
*mail-send
2} 8hat is maildir?
Eaildir is a mailbo! format created b& an :ernstein to address the
shortcomin"s of the mbo! format. A maildir mailbo! is a director&containin" three subdirectories, ne#, cur, and tmp. ach messa"e in a
maildir mailbo! is in a separate file in one of the subdirectories,
dependin" upon its status$ ne# is for unread messa"es, cur is for
messa"es that have been seen, and tmp is for messa"es in the process
of bein" delivered.
3} 8hat is procmail?
procmail is a popular Eessa"e eliver& A"ent =EA. The function of
an EA is to accept a messa"e from the ETA for a specific user or
mailbo!, and deliver the messa"e accordin" to the users desires.
procmail can be used to RfilterS messa"es b& the content of various
header fields or the bod& of the messa"e.
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"} 8hich =roups and Users are re!uired to start C4I rootP !it bin0m&s*ladmin
reload
The ne!t time &ou lo" in, &ou #ill use &our ne# pass#ord
9} 8here is the data stored in a Cy-< database?
E&(/ uses files to store data. These files are under the
data0databasename director&, #here databasename is the name of the
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database. There are three file t&pes$ .I(E, .4%E, and .I(. The .4%E
file contain the table schema. The .I( is the file that actuall& holds
the data. The .I(E file is the file that provides *uic5 access bet#een
the t#o of them.
1'} 7plain the terms @mys!limportA/ @mys!ldumpA/
@mys!ladminA and @mys!lcheckA?
m&s*limport for importin" data files, m&s*ldump for ma5in" bac5ups,
m&s*ladmin for server administration, and m&s*lchec5 for chec5in"
the inte"rit& of the database files.
11} 5ow you will determine the options which are used bymys!l?
Fm&s*l +help
12} 5ow you will determine the #ersion o Cy-
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9ou as5ed for help about help cate"or&$ RContentsS
4or more information, t&pe help Qitem3, #here Qitem3 is one of
the follo#in" cate"ories$
AdministrationColumn T&pes
ata efinition
ata Eanipulation
4unctions
eo"raphic features
Transactions
1&} 8hat is Cy-< uery >rowser?
The E&(/ uer& :ro#ser is a "raphical tool desi"ned to provide a
user friendl& environment in #hich to construct and e!ecute (/
statements.
1)} 7plain @4UGLIN6:7C7NA attribute?
AUTD[INC%ENT attribute ma& be added to an inte"er column
definition to create a column for #hich E&(/ automaticall&"enerates a ne# se*uence number each time &ou create a ne# ro#.
There ma& be onl& one AUTD[INC%ENT column per table, the
column must be inde!ed, and the column must be defined as NDT
NU//.
1+} 8hat this command @mys!ladmin status #ariablesA will
do?
This command #ill displa& a brief status messa"e, follo#ed b& the list
of server s&stem variables.
19}7plain @6576F 4>
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structure and contents. It #or5s for E&I(AE and Inno: tables. 4or
E&I(AE tables, it also updates the inde! statistics. If the table is a
vie#, CC@ TA:/ verifies the vie# definition.
2'} 7plain @:704I: 4>
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2%}8hat is the use o @IN,G:C4IGNL-657C4
;atabaseA?
The IN4D%EATIDN[(CEA database provides access to database
metadata.IN4D%EATIDN[(CEA is a Rvirtual databaseS in the
sense that it is not stored anhere on dis5. :ut li5e an& other
database, it contains tables, and its tables contain ro#s and columns
that can be accessed b& means of (/CT statements.
2&} 8hat is @binary backupA?
A binar& bac5up is a cop& of the files in #hich database contents are
stored. Cop&in" these files preserves the databases in e!actl& the sameformat in #hich E&(/ itself stores them on dis5. %estoration
involves cop&in" the files bac5 to their ori"inal locations. Techni*ues
for ma5in" binar& bac5ups include file cop& commands.
2)} 8hat is @tet backupA?
A te!t bac5up is a dump of database contents into te!t files.
%estoration involves loadin" the file contents bac5 into databases b&
processin" them throu"h the server. Techni*ues for ma5in" te!tbac5ups include the (/CT INTD DUT4I/ (/ statement,
m&s*ldump, and E&(/ Administrator.
2+} 5ow you will $rant the -7
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3'} 7plain the command @-5G8 =:4N- ,G:
rootPlocalhostVA
It #ill sho# the account has "lobal, database-level, and table-level
privile"es.
GC64 400 -7:B7:
1} I stored a cookie on the browserV why cant I see it?
4irst, chec5 to ma5e sure &ou spelled the coo5ie name correctl&. Ne!t,
ma5e sure the bro#ser has coo5ies enabled. Also, if &ou specified a
root path for the coo5ie, ma5e sure that the ( or servlet readin" the
coo5ie is in that path. %emember, too, that if &ou dont "ive the coo5ie
a specific e!piration time, the coo5ie #ill vanish #hen the user shuts
the bro#ser do#n.
2}8hy is a new obQect created whene#er I call
QspJuse>ean?9ou probabl& for"ot to specif& a scope for the bean.
%emember, the default scope for a bean is pa"e, and all beans #ith
pa"e scope disappear #hen the pa"e finishes e!ecutin".
3} 8hen do I use ( and when do I use W?
Althou"h &ou can use these operators interchan"eabl&, it is a "ood idea
to use an operator that indicates the 5ind of data bein" accessed. 4or
e!ample, if &ou are accessin" a bean propert&, use the . operator. If &ou
are accessin" a map value or an arra& inde!, use the ;B operator. There
are plent& of times #hen &ou brea5 this rule, especiall& in cases #here
&ou #ant a map to loo5 li5e it is a bean, &ou #ant thin"s to ma5e sense
to the ne!t person #ho reads &our code. 9ou ma& 5no# the t&pes of all
the variables, but the ne!t person ma& not.
"}5ow do I coni$ure omcat to work with II- and N
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4ollo# the standard instructions for #hen the isapi[redirector.dll
Confi"ure II( to use Rinte"rated #indo#s securit&S
In server.!ml, ma5e sure &ou disable tomcat authentication$
QConnector port>S227j enable/oo5ups>SfalseS redirectort>SJJ1jprotocol>SA0SfalseS 03
%}7plain the concepts o omcat -er#let 6ontainer(
+ Tomcat (ervlet Container is a servlet container. The servlets runs in
servlet container. + The implementation of ava (ervlet and the ava
(erver a"es is performed b& this container. + rovides TT #eb
server environment in order to run ava code. + %educes "arba"ecollection + Native 'indo#s and Uni! #rappers for platform
inte"ration
&} 8hy do I $et a 6lassNot,ound7ception when I try to use
the -hoppin$6art class?
The ( en"ine probabl& cant see the class in its classpath. Tomcat
uses the s&stem classpath, so if (hoppin"Cart.class is visible
some#here in the s&stem classpath, the& should see it.
)}8hat is omcat?
Tomcat is a ava (ervlet container and #eb server from a5artha
proOect of Apache soft#are foundation. A #eb server sends #eb pa"es
as response to the re*uests sent b& the bro#ser client. In addition to
the static #eb pa"es, d&namic #eb pa"es are also sent to the #eb
bro#sers b& the #eb server. Tomcat is sophisticated in this respect, as
it provides both (ervlet and ( technolo"ies. Tomcat provides a "ood
choice as a #eb server for man& #eb applications and also a free
(ervlet and ( en"ine. Tomcat can be used standalone as #ell as
behind other #eb servers such as Apache httpd.
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+} 8hat is Masper?
asper is a pro"ram to read the .class files in binar& format. This
pro"ram can "enerate A(CII files , #hich can be used alon" #ith
asmin Assembler. asper is intended for "eneratin" input into a class
file bro#ser #hich can produce the hierarch& of inheritance and
composition maps from the .class files.
9}6an I set Ma#a system properties dierently or each
webapp?
No. If &ou can edit Tomcats startup scripts, &ou can add R-S options
to ava. :ut there is no #a& to add such properties in #eb.!ml or the
#ebapps conte!t.
MJ
M?