with IBM Corp....A vailable cloud storage solutions IBM XIV Storage System Gen3 version 1 1.6.2 can be integrated with various independent softwar e vendor (ISV) platform, application,

IBM XIV Storage System Gen3Version 11.6.2

Release Notes

IBM

Second Edition (January 2017)

This edition applies to IBM XIV Storage System Gen3 version 11.6.2. Newer document editions may be issued forthe same product version in order to add missing information, update information, or amend typographical errors.The edition is reset to 'First Edition' for every new product version.

© Copyright IBM Corporation 2011, 2017.US Government Users Restricted Rights – Use, duplication or disclosure restricted by GSA ADP Schedule Contractwith IBM Corp.

Contents

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1What's new in version 11.6.2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1Hot upgrade from earlier versions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1Management and automation tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2Change log . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Version 11.6.2 (December 2016) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4Version 11.6.1.a (March 2016) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7Version 11.6.1 (December 2015) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7Version 11.6.0.b (June 2015) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Fixes and features of earlier versions . . . . . . . . . . . . . . . . . . . . . . . . . . . 11Limitations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11Known issues. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13Related information and publications . . . . . . . . . . . . . . . . . . . . . . . . . . . 19Getting information, help, and service . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Notices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21Trademarks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

© Copyright IBM Corp. 2011, 2017 iii

iv IBM XIV Storage System Gen3 – Release Notes

Overview

IBM® XIV® Storage System Gen3 is a high-end, grid-scale, hostspot-free diskstorage system that delivers high performance, smart scaling, distributed data,automatic load balancing, and a multitude of advanced enterprise-class storagefeatures and capabilities – all with extreme ease of use.

IBM XIV is ideal for cloud environments, offering high service levels for dynamicworkloads and easy hyper-scaling, while supporting multi-tenant environments,flexible consumption models, and robust cloud automation and integrationcapabilities. IBM XIV offers security and data protection through advanced remotemirroring, hot encryption, and self-healing mechanisms.

Licensed XIV Gen3 systems support IBM Real-time Compression™ and IBMRandom Access Compression Engine (RACE) technology, enabling considerableincrease of usable capacity per rack. The 281x-314 Gen3 model includescompression as a built-in licensed feature, together with specific hardwareimprovements for attaining optimized performance when using data compression.

For more detailed information about IBM XIV Storage System Gen3, refer to itsuser documentation and online information.

What's new in version 11.6.2Software version 11.6.2 enhances the operation of existing functional features andresolves miscellaneous issues.

General availability date: 12 December 2016

For more information about the fixes in version 11.6.2, see “Change log” on page 3.

Important: Unless using IBM Hyper-Scale Manager version 5.1.1 or later tomonitor and manage the storage system, XIV Gen3 version 11.6.2 requiresmandatory upgrade of the XIV Management Tools to version 4.8.0.4. For moreinformation, see “Management and automation tools” on page 2.

Hot upgrade from earlier versionsVersion 11.6.2 supports direct hot upgrade from the following XIV Gen3 softwareversions.v 11.6.1, 11.6.1.av 11.5.2.bv 11.4.2.av 11.1.1

Other 11.x.x versions can be upgraded to 11.6.2 by applying consecutive hotupgrades, depending on the version in use.

Note: These hot upgrade paths are valid for the time of the general availability(GA) date of version 11.6.2. However, hot upgrade from additional earlier versionscould be supported later on. For up-to-date information, contact IBM Support.

© Copyright IBM Corp. 2011, 2017 1

The upgrade must be performed only by an authorized IBM service technician.

Note: The system e-license may automatically prompt in the management GUIupon the first post-upgrade operation, if the e-license was updated since it was lastaccepted. In such a case, the new e-license must be accepted before any GUIoperation can be performed.

Before initiating the upgrade, some preparation steps are required. For moreinformation, see 'Non-disruptive code load' in the IBM XIV Gen3 Product Overviewpublication.

Management and automation toolsIBM XIV Gen3 version 11.6.2 can be managed and monitored with the followingsoftware management tools.v IBM Hyper-Scale Manager version 5.1.1 or later – provides an advanced and

brand-new web-based graphical user interface (GUI) from which one or moreXIV systems (and any other IBM Spectrum Accelerate™ Family system) can bemanaged and monitored in real time from a web browser.

v IBM XIV Management Tools version 4.8.0.4 or laterv IBM XIV Mobile Dashboard (for monitoring only) version 1.4.0.1 or later

Important: Although earlier management tool versions may be able to detect XIVsystems of version 11.6.2, the latest XIV functional features and/or ManagementTools security updates are available only in the versions specified above.

IBM XIV Gen3 can also be managed from its command-line interface (CLI) orthrough its RESTful application programming interfaces (APIs).

XIV customers are entitled to free use of these management tools, which can bedownloaded at any time from the IBM Fix Central website (ibm.com®/support/fixcentral).

The Mobile Dashboard application can be downloaded and installed at any timeand from Apple Store (iOS version) or Google Play (Android version).

IBM Spectrum Control Base Edition

IBM XIV Gen3 version 11.6.2 is supported by IBM Spectrum Control Base Editionversion 3.0.3 or later, which provides the following VMware platform integrationtools.v IBM Storage Provider for VMware VASAv IBM Storage Enhancements for VMware vSphere Web Clientv IBM Storage Plug-in for VMware vCenter Orchestratorv IBM Storage Management Pack for VMware vCenter Operations Manager

For more information, see IBM Spectrum Control Base Edition on IBM KnowledgeCenter (ibm.com/support/knowledgecenter/STWMS9).

2 IBM XIV Storage System Gen3 – Release Notes

http://www.ibm.com/support/fixcentral

https://itunes.apple.com/us/app/ibm-xiv-mobile-dashboard-for/id503500546?mt=8

https://play.google.com/store/apps/details?id=com.ibm.xiv.mobile.android

http://www.ibm.com/support/knowledgecenter/STWMS9

http://www.ibm.com/support/knowledgecenter/STWMS9

XIV customers are entitled to free use of IBM Spectrum Control Base Edition,which can be obtained at any time from either the IBM Hyper-Scale Manager 5.x.xsoftware package or from the IBM Fix Central website (ibm.com/support/fixcentral).

Available cloud storage solutions

IBM XIV Storage System Gen3 version 11.6.2 can be integrated with variousindependent software vendor (ISV) platform, application, virtualization, and cloudenvironments.

To facilitate this integration, IBM provides the following software solutions, alsoreferred to as cloud storage solutions.

Cloud storage solution Version Compatibility note

IBM Storage Host Attachment Kit 2.6.0 or later Available for IBM AIX®,HP Unix, Linux,Oracle Solaris, and MicrosoftWindows Server

IBM XIV Provider for Microsoft WindowsVolume Shadow Copy Service (VSS)

2.8.0.1 or later

IBM XIV Storage Replication Adapter(SRA)

2.3.0 or later For use with VMware vCenterSite Recovery Manager

IBM Storage Driver for OpenStack 1.8.0 or later Version 1.8.0 supports onlythe OpenStack Newton release

IBM Storage Enabler for WindowsFailover Clustering

1.2.0 or later Version 1.2.0 does not supportcompressed volumes (throughthe IBM Real-timeCompression feature)

IBM Storage Management Pack forMicrosoft System Center OperationsManager

2.6.0 or later

XIV customers are entitled to free use of the IBM cloud storage solutions, whichcan be downloaded at any time from the IBM Fix Central website(ibm.com/support/fixcentral).

For more information about the available cloud storage solutions for XIV, seePlatform and application integration on IBM Knowledge Center (ibm.biz/BdXy4c).

Change logThis change log summarizes the enhancements and fixes in the different 11.6.xcode level versions of IBM XIV Storage System Gen3.

Note: New functional features of these versions are only briefly summarized. For adetailed summary of the new functional features of a specific version, refer to the'What's new' section of its release notes.

Overview 3



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Version 11.6.2 (December 2016)Version 11.6.2 of IBM XIV Storage System Gen3 resolves the following issues.

Ticket ID Description

SYS-276312 Fixed: In rare cases when using synchronous or asynchronousmirroring, an I/O operation might not to be recorded correctly onthe slave system when a very small amount of data needs to besynchronized. This will be detected and fixed automatically bythe periodic scrub process.

Severity: HIPER

Affected versions: 11.0.0 or later

SYS-275731 Fixed: Common OpenSSL security issues.

For more information about these security issues, seeCVE-2015-3194, CVE-2015-3195, CVE-2015-3196, CVE-2016-2107,CVE-2016-2108, CVE-2016-2109, and CVE-2016-2176 on theCommon Vulnerabilities and Exposures (CVE) informationwebsite (cve.mitre.org).

Severity: High Impact


SYS-275992 Fixed: Cache nodes of storage systems with compressed volumesmight fail during an upgrade operation.

Note: This does not occur when upgrading to software version11.6.2.



SYS-276233 Fixed: A VVol-based virtual machine, which includes a volumewith snapshots, that is migrated within the same IBM XIV storagesystem using VMware Storage vMotion, is exposed to a potentialundetected data corruption issue. A read from a volume orsnapshot of a migrated VVol-based virtual machine may returnincorrect data.



SYS-276688 Fixed: Common OpenSSH security issues.

For more information about these security issues, seeCVE-2016-0777 and CVE-2016-0778 on the CommonVulnerabilities and Exposures (CVE) information website(cve.mitre.org).




https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-3194










SYS-277077 Fixed: The ‘switch role’ mirror operation for a consistency groupis not blocked if any of the volumes on the previous masterremained mapped. This would cause a volume that is now aslave to remain mapped (as opposed to the requirement forunmapping the slave volume) and the data on this volume mightbecome corrupted.

Note: To prevent this issue from occurring, this ‘switch role’operation is blocked starting from version 11.6.2. For moreinformation, see “Limitations” on page 11.



SYS-278540 Fixed: In very rare cases that involve timing of user read/writecombined with internal system procedure, a user read I/Ooperation might not be acknowledged and the compression nodethat is handling the I/O operation might fail. The othercompression nodes continue to work as usual and their I/Ooperations continue to be served. The failed compression noderevival must be performed by IBM Support.



SYS-281678 Fixed: In rare and specific cases, the asynchronous remotemirroring sync job might get stuck with a single partition leftwithout synchronization.



SYS-281984 Fixed: In rare cases, a particular software error might lead toInfiniBand interconnect communication error between one of theinterface nodes and one of the cache nodes, leading to hostdisconnection.



SYS-266936 Fixed: When starting and completing a transformation fromcompressed state to uncompressed state or vice versa, UnitAttention is not raised for all hosts that are mapped to thetransformed volume.

Severity: Moderate


Overview 5


SYS-276859 Fixed: The XCOPY (Extended Copy) SCSI command, which ispart of the VMware vSphere API for Array Integration (VAAI)specification, is not supported with compressed volumes. Thisimpacts the speed of VMware environment copy operations byautomatically falling back to a host-based copy. The impactedcopy operations are virtual machine cloning, virtual machinecreation from a template, and vSphere Storage vMotion, withinthe same storage array.

Severity: Moderate


SYS-276398 Fixed: The event saver node that is responsible for sending eventsmight fail when handling a large number of events. This hasminimal impact on the system as there is an event saver instanceon each of the other XIV modules.

Severity: Service

Affected versions: 11.6.0.b or later

SYS-272799 Fixed: Media errors on the disk might cause the scrub process tostop running.

Severity: Service

Affected versions: 11.5.0.a or later

SYS-276062 Fixed: Soft and hard size values appear incorrectly in thePOOL_RESIZE_THIN event. The value of the soft size is displayedfor the hard size, and vice versa.

Severity: Service

Affected versions: 11.6.0.b or later

SYS-280256 Fixed: In some cases when a mirroring relationship is deleted, themanagement GUI might display a blank page.

Severity: Low


Command-line interface (CLI) enhancement that has been added in version 11.6.2:


SYS-283346 Enhancement: Added volume listing filtering by World WideName (WWN). The wwn parameter can be used with the vol_listcommand in the following format: vol_list wwn=<wwn number>.The WWN number of all volumes can be obtained by issuing thefollowing command: vol_list -f name,wwn


Version 11.6.1.a (March 2016)Version 11.6.1.a of IBM XIV Storage System Gen3 resolved the following issues.


SYS-277205 Fixed: In rare cases where a module fails and another moduleboots slowly during a microcode hot upgrade, the cache nodesmight fail.



SYS-277761 Fixed: GNU C Library vulnerability issue (not specific to XIVsystems): GNU C Library (glibc) is vulnerable to a stack-basedbuffer overflow, caused by improper bounds checking by the NSSDNS backend for the getaddrinfo() function when performingdual A/AAAA DNS queries. By sending a specially crafted DNSresponse, a remote attacker could overflow a buffer and executearbitrary code on the system, or cause the application to crash.

For more information about this security issue, see CVE-2015-7547on the Common Vulnerabilities and Exposures (CVE) informationwebsite (cve.mitre.org).



Version 11.6.1 (December 2015)Version 11.6.1 of IBM XIV Storage System Gen3 introduced Turbo Compression inthe new 281x-314 XIV hardware model, as well as compression enhancements forall XIV Gen3 models.

Fixes in version 11.6.1:


SYS-252858 Fixed: In rare cases, when a data redistribution process runs inparallel with a synchronous or asynchronous mirroringsynchronization process, host disconnection might occur.



SYS-271569 Fixed: In rare cases, a failure of an SSD cache drive might resultin host disconnection.



Overview 7



SYS-273223 Fixed: In rare cases, a system with an asynchronous mirrorrelation might fail if the target connectivity is down and a newasynchronous mirror is created with the Offline init optionselected.



SYS-275362 Fixed: In extremely rare cases, a race condition might cause dataloss in a certain compressed volume. As a result, the volume goesoffline.



SYS-271892 Fixed: When setting Microsoft Azure Site Recovery protectionbetween two sites using storage area network (SAN) replication, ifa non-2810 XIV machine type is selected as the storage provideron either the local site or remote site, protection operations fail.

Severity: Moderate


SYS-273769 Fixed: In rare cases, a non-critical thread might enter an endlessloop that affects performance. The impact on performance couldrange from negligible to significant, depending on the systemwork load.

Severity: Moderate


SYS-274270 Fixed: strongSwan vulnerability issue (not specific to XIVsystems): strongSwan could allow a remote authenticated attackerto obtain sensitive information, caused by an error in IKEv2connections related to server authentication with a certificate andEAP or pre-shared keys. An attacker could exploit thisvulnerability to obtain user credentials and other sensitiveinformation.


Severity: Moderate





SYS-274413 Fixed: Net-SNMP vulnerability issue (not specific to XIV systems):Net-SNMP is vulnerable to a denial of service, caused byincompletely parsed VarBind variables being left in the list ofvariables by the snmp_pdu_parse() function. A remote attackercould exploit this vulnerability to cause the application to crashor possibly execute arbitrary code on the system.


Severity: Moderate


SYS-273234 Fixed: In a rare cases, a memory corruption might cause a certainsoftware component to fail, resulting in a slight decrease inperformance of compressed volumes.

Severity: Service


SYS-273704 Fixed: In some cases, management systems that use SMI-S forcontrolling the XIV system are unable to control it.

Severity: Service

Affected versions: 11.0.0

SYS-273895 Fixed: When an LDAP directory user tries to accept the license fora new system or after a microcode upgrade that includes a newlicense, the operation fails with the error: ILLEGAL_NAME

Severity: Service

Affected versions: 11.0.0

SYS-273902 Fixed: Users with Application Admin role might be unable tocreate a snapshot of a consistency group. This occurs if theconsistency group contains one or more volumes that are notmapped to a host that is associated with a user group thatcontains these users.

Severity: Service


SYS-274349 Fixed: Some systems might stop sending heartbeat info to IBMSupport. As a result, IBM Support might not have completeinformation when handling arising issues.

Severity: Service


Security improvement in version 11.6.1:

Overview 9



SYS-273930 Since version 11.5.0, users with Storage Administrator role wereable to create Security Administrator users, while users withSecurity Administrator role were able to change the password ofthe default administrator.

Starting from version 11.6.1:

1. Users with Security Administrator role cannot changepassword of the default administrator.

2. Only the default administrator can create, rename, change thepassword of, or delete Security Administrator accounts.

Version 11.6.0.b (June 2015)Version 11.6.0.b of IBM XIV Storage System Gen3 was the first major release of the11.6 code level that introduced the following primary features.v IBM Real-time Compressionv Support for integration with Microsoft Azure Site Recoveryv Automatic shutdown in extreme overheating conditions

Fixes in version 11.6.0.b:


SYS-269182 Fixed: In extremely rare situations on systems with SSD cachingenabled, when two read operations are sent by the host to thesame address, the second read operation might return incorrectdata from the cache, which could result in undetected datacorruption. Subsequent reads to the same address (after the datais no longer in the cache) returns the correct data.



SYS-252743 Fixed: When entering several certificates to the certificateparameter, ipsec_connection_* XCLI commands processes onlythe first certificate.

Severity: Service


SYS-265572 Fixed: If any of the parameters of pool_change_config are invalid,the command might start running and then fail halfway through.

Severity: Service


SYS-266212 Fixed: If a solid-state drive fails during the encryption process,the SSD_HAS_FAILED_WHILE_ENABLING_ENCRYPTION event might notbe issued.

Severity: Service




SYS-266220 Fixed: The format=full parameter on the XCLI help command isnot supported.


Severity: Service

SYS-266221 Fixed: The ldap_user_list role=storageadmin XCLI commanddoes not list domain administrators.

Severity: Service


SYS-266476 Fixed: When using the muti-tenancy feature in LDAPauthentication mode, a domain with which users are currentlyassociated cannot be deleted.

Severity: Service


SYS-266853 Fixed: In the XCLI help, the descriptions of the domain_manageand domain_move_gp commands are incorrect.

Severity: Service


SYS-267911 Fixed: IBM Hyper-Scale Manager supports LDAP UPN modeonly when there are no domains configured on the system. Ifdomains are configured on the system, LDAP UPN mode is notsupported.

Severity: Service


Fixes and features of earlier versionsIBM XIV Storage System Gen3 version 11.6.2 includes all the features and fixes thatwere included in previous 11.x.x versions.

To obtain information regarding previously introduced XIV Gen3 features or issuesthat were resolved in previous versions, see the XIV Gen3 release notes page onIBM Knowledge Center (ibm.com/support/knowledgecenter/STJTAG).

LimitationsThe following functional limitations apply to IBM XIV Storage System Gen3 andmay remain in effect in future XIV software versions.

Overview 11

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Limitations with IBM Real-time Compression

Note: For information about specification-related functional boundaries, such asmaximum number of volumes and hosts per storage system, refer to the IBM XIVStorage System Gen3 specification sheet document, which can be provided to IBMcustomers under non-disclosure agreement (NDA).

The following limitations apply to the IBM Real-time Compression feature whenused on XIV Gen3 systems:v The minimum volume size that can be compressed is 51 Gigabytes (GB). The

compression option is blocked for smaller volumes.v The maximum volume size that can be compressed is 10 Terabytes (TB). The

compression option is blocked for larger volumes.v Up to 1024 volumes can be compressed on a single XIV system.v Only thin-provisioned volumes can be compressed.v Shrinking a compressed volume is not supported.v Snapshots cannot be converted from compressed to uncompressed and vice

versa. Snapshots that already existed before a volume was converted fromnon-compressed to compressed are not converted and are not available with theconverted volume.

v When migrating volumes using IBM Hyper-Scale Mobility, compression ordecompression operations can only begin after the migration is complete.

v Locked volumes must be unlocked before compression or decompression canbegin.

v In a mirroring relation, both the source and target volumes must be compressed,or both must be uncompressed.

v Mapping a host to a compressed volume on a slave node in a mirrored system isnot permitted.

v To convert a mirrored volume from uncompressed to compressed (or vice versa),the mirroring relationship for that volume must first be removed and thenrecreated after the conversion.

v When two-way or three-way mirroring is used, compressed volumes on thesecondary or tertiary system cannot be mapped to hosts, except when thesevolumes become primary volumes after a failover operation. Before any failoveroperation (including failover testing) compressed primary (master) volumesmust first be unmapped from their hosts.

v IBM PowerHA® Enterprise Edition is not supported.v The latency of synchronously mirrored compressed volumes could be higher

than that of synchronously mirrored uncompressed volumes. As a result, if thedistance between the production and recovery sites is extremely large, hostdisconnections might occur. It is therefore recommended to test the latency on atest volume before using synchronous mirroring with compressed volumes inthe production environment.

v The system continuously assesses potential saving ratio at a pace ofapproximately 20 volumes per hour. Until the initial assessment of anynon-compressed volume is complete, its potential saving ratio is not displayed.

v The calculated potential saving percentage of a decompressed volume (convertedfrom compressed to non-compressed) could be different than the savingpercentage that was originally calculated for the same volume prior to itscompression. This occurs if most of the data on the volume comprises zeros,while other data is sparsely distributed.


v VMware vSphere Virtual Volumes (VVols) are not supported with compressedvolumes.

v Data migration CLI commands (dm_activate, dm_deactivate, dm_define,dm_delete, dm_list, dm_test) are not supported with compressed volumes.

Limitations with IBM Hyper-Scale Mobility

The following limitations apply to the IBM Hyper-Scale Mobility (volumemigration) feature when used with XIV Gen3 systems:v Can be used only with systems that are located within the same datacenter.v Cannot be used on a volume that belongs to a consistency group. The volume

must first be removed from the consistency group.v Does not apply to volume snapshots. When the migration is changed to proxy

state, all snapshots of the pertinent migrated volume are deleted automatically.v Does not migrate volume mirroring relationships. Before a volume can be

moved, its mirroring relationship must be deleted.

Known issuesThis section details the known issues in IBM XIV Storage System Gen3, along withpossible solutions or workarounds (if available).

The following severity levels apply to known issues:v HIPER – High Impact Pervasive. A critical issue that IBM has either fixed or

plans to fix promptly. Requires immediate customer attention or code upgrade.v High Impact – Potentially irrecoverable error that might impact data or access to

data in rare cases or specific situations/configurations.v Moderate – Limited functionality issue and/or performance issue with a

noticeable effect.v Service – Non-disruptive recoverable error that can be resolved through a

workaround.v Low – Low-impact usability-related issue.

Important:

v The issues listed below apply to version 11.6.2 or earlier versions. As long as anewer version has not yet been released, a newer release notes edition forversion 11.6.2 might be issued to provide a more updated list of known issuesand workarounds.

v When a newer version is released for general availability, the release notes ofversion 11.6.2 will no longer be updated. Accordingly, check the release notes ofthe newer version to learn whether any newly discovered issues affect version11.6.2 or whether the newer version resolves any of the issues listed below.

Overview 13

Ticket ID SeverityAffectedversions Description

SYS-260642 HighImpact

11.4.0or later

The following XCLI commands require a user name as aparameter, but appear to run successfully even if the specifieduser does not exist:

v encrypt_recovery_key_generate

v encrypt_keyserver_rekey

v encrypt_recovery_key_rekey

Workaround: Before running these commands, use the user_listXCLI command to make sure that the user exists.

SYS-267506 HighImpact

11.5.1or later

On systems with 6 TB drives, a single restore of a volume from asnapshot or a consistency group (CG) cannot be handled whenthe total hard size of the volumes involved (including all theirsnapshots) exceeds 90% of the system's entire usable capacity.

Workaround: Avoid creating a single volume or a single CG witha total hard size that exceeds 50% of the system usable capacity.

SYS-253004 Moderate 11.0.0or later

Resizing a pool (reducing its volume capacity) does not triggerthe STORAGE_POOL_VOLUME_USAGE_INCREASED event when crossingthe preset threshold.

Workaround: No workaround is currently available. Accordingly,use caution when resizing down a storage pool.


In a multi-site mirroring relation, if the destination remainsconnected to the source after the source is disconnected from thehost and the secondary source, establishing an asynchronousmirror from the secondary source to the destination requires afull resynchronization.

Workaround: No workaround is currently available.


When changing a volume to read only, the system does not raisea SCSI Unit Attention to make the host aware of the change.



If a mirroring-related snapshot (LRS) of an active xmirror relationis deleted on the source volume due to lack of space in thestorage pool, subsequent xmirror_activate commands on thesource volume fail with a misleading return code(XMIRROR_SLAVE_HAS_MORE_RECENT_DATA).

Workaround:

1. Remove the asynchronous source-destination mirror relation.2. Ensure that the storage pool has enough space on the source.3. Reestablish the asynchronous source-destination mirror

relation.4. Reestablish and activate the xmirror relation.

During this process, the source-secondary synchronous mirrorrelation can continue working.




The multi-tenancy feature does not support Sun directory orOpen LDAP group objects. Static groups reflecting domainadministrators fail to log in, and receive an unrecognized rolecompletion code.

Workaround: Instead of the an LDAP group object attribute, usethe description string as hard-coded value per user. For moreinformation, refer to the IBM XIV Storage System Architecture andImplementation Redbook.


When a compressed volume is in a three-way mirroringrelationship, any crash of the source volume might result in asituation where the tertiary site volume has more recent datathan on the secondary site volume. In such a case, the regularrecovery process does not work.

Workaround: To resolve this issue:

1. Disable the three-way mirroring.2. Recreate asynchronous mirroring with the tertiary site

mirrored to the primary site.3. Wait for the volume to synchronize.4. Reestablish the three-way mirroring.


The time required for decompressing a volume is proportional tothe volume size, and the time required for compressing a volumeis proportional to the amount of data that the volume contains.As a result, decompressing a volume is typically much slowerthan compressing the same volume.


SYS-257063 Service 11.3.0or later

When using IBM Hyper-Scale Mobility (volume migration) and ahost is mapped to both the source volume and the destinationvolume, the system does not display a warning upon theunmapping of the source volume from the host.

Workaround: Prior to unmapping the source volume, verify that:

v The host is mapped to the volume on the destination system.v I/Os are running on that path.

This can be done from the host side or by using the XIV statistictools on the destination system.


Deleting a user certificate reverts the system to the genericcertificate instead of to the unique system certificate.

Workaround: Set the system-unique certificate as a default beforeremoving the user certificate.

Overview 15



When issuing the encrypt_enable XCLI command immediatelyafter defining a key server:

v The command returns Command executed successfully.v Encryption is not enabled.v The ENCRYPT_ENABLE_NOT_COMPLETED event is issued.

Workaround: Wait 10 seconds and then retry.


In a multi-site mirroring relation, if the secondary source isdeleted by using the delete_xmirror command with force=yes, asubsequent xmirror_activate command might return a successreturn code, even though no secondary source volume is defined.



Domain administrators from different domains that share aresource, can view and delete the metadata of that resource.



snmpwalk for volume statistics may take a long time whenmultiple volumes are defined.



When associating separate LDAP groups to separate domains, anLDAP directory user cannot belong to more than one group if notmentioned specifically by the group name in the format ofuser@domain1/domain2.

If a user is not defined in such a way and the memberOf fieldcontains more than one group, an LDAP_USER_CONFIG_ERROR eventis issued.



In IP filtering, FQDN host names are not supported by theip_access_group_remove_address command.

Workaround: Use an IP address instead.


When using the multi-tenancy feature, the system does not blockapplication administrators, who belong to user groups in theglobal domain, from being designated as IBM Hyper-ScaleManager users.

Workaround: Remove any application administrator from the listof IBM Hyper-Scale Manager users.


When working with IP filtering, a subnet cannot be added to anIP access group if an IPO, that is part of the subnet, alreadyexists in the access group.

Although the ip_access_group_add_address command is issuedwithout an error, the subnet is not added.





CIM is not multi-tenant aware and cannot be used by a domainadministrator.

Workaround: Use the credentials of a global (non-domain) user,and set the domain access policy to OPEN (default policy).


IP filtering does not work for an IP range.

Workaround: Define an IP range by using an IP mask.


When using IP filtering, there is no validation that a valid IPaddress is entered to the IP Access Group.



When adding IP addresses to an IP Access Group for IP filtering,two addresses cannot be added with the same IP, but withdifferent netmasks.



When using the ldap_user_list command with a validadministrator role that does not allow input for this particularcommand, the status string does not indicate the invalid inputcorrectly: Illegal value 'string' for argument 'argument' ofcommand 'command'.



When three-way mirroring is being used, trying create a mirrorsnapshot on the asynchronous secondary system results in afailure (error event: XMIRROR_SNAPSHOT_MIRROR_NOT_SUPPORTED)because such operation is not supported with three-waymirroring. The prompted error message, however, is incorrect:Volume is part of an xmirror, snapshot mirrors are notsupported for xmirrors. Snapshot mirrors are supported on asynchronous secondary system.



1024-bit SSH keys that were in use prior to a software upgrade toversion 11.6.x are no longer valid because 2048-bit SSH keys arerequired starting from version 11.6.x. Trying to use an 1024-bitSSH results in the following error message: WARNING: REMOTEHOST IDENTIFICATION HAS CHANGED!

Workaround: Remove the old SSH key from the$HOME/.ssh/known_hosts file, or delete the file entirely.


When decompressing a compressed volume that belongs to aperformance class, the decompression might take longer time tocomplete because the volume performance is constrained by theperformance class.

Workaround: Remove the performance class assignment until theconversion completes.

Overview 17



When a compressed VMFS5 volume is being converted back touncompressed state, the volume does not support VMware VAAISCSI commands. These commands become supported again afterthe conversion process is complete.

Workaround: To avoid this issue, the VMFS5 volume type mustfirst be converted from ATS Only to ATS + SCSI reservation. Usethe following ESXi CLI command to disable ATS locking:vmkfstools --configATSOnly 0device-path

For more information, see VMware KB article 2006858(kb.vmware.com/kb/2006858).


Obtaining the initial compression analysis of potential capacitysaving for 1000 volumes might take up to 48 hours, dependingon the load in the system.



When volume compression is enabled, the general expectationwould be that the cache hit ratio should increase, since some ofthe data is compressed and therefore the cache can contain moredata. However, depending on the workload mix, the cache hitratio might start to decline after a certain system load isexceeded.

Workaround: Reduce the system load. For example, migratesome volumes to less loaded systems.


When changing or switching a mirror relation role whilecompressed volumes are used, after the secondary systembecomes a the primary system, the correct compression rate forthe new primary system is not shown immediately.



Cache hit latency for compressed volumes, as displayed in XIVTOP, is consistently incorrect and much higher than the actualone.

Workaround: In the XIV performance view, use an aggregatefilter and do not select the Hit or Miss filters. For higheraccuracy, use external tools to measure the latency on the host.


In some rare cases, upon the enabling of drive encryption, asolid-state drive (SSD) might fail, resulting inCOMPONENT_TEST_OF_SSD_HAS_FAILED event for this drive. The SSDcache on the related module remains unavailable until theproblem is fixed.

Workaround: No workaround is currently available. For apossible solution, contact IBM Support.


http://kb.vmware.com/kb/2006858



In a Microsoft Azure Site Recovery configuration, when aFailover operation is followed by Disable Protection, MicrosoftSystem Center Virtual Machine Manager (SCVMM) might promptan exception such as: Replication group '$cgname' wasunexpectedly found to be in a replication relationship.

The exception is the result of a failure to automatically delete themirror relationship on the target location. This might happeneven if the communication between the source and target sites isoperational.

Workaround: Using XIV CLI or GUI, delete the consistencygroup mirror from the storage array on the target location beforeinvoking Disable Protection. This can be applied before or afterthe exception occurs.


Error code MCL_TIMEOUT_EXPIRED is returned when attempting touse the cg_move command to move a consistency group that ispart of a group pool.


Related information and publicationsYou can find additional information and publications related to IBM XIV StorageSystem Gen3 on the following information sources.v IBM XIV Storage System marketing website (ibm.com/systems/storage/disk/

xiv)v IBM XIV Storage System on IBM Knowledge Center (ibm.com/support/

knowledgecenter/STJTAG)v IBM Storage Redbooks® website (redbooks.ibm.com/portals/storage)

Getting information, help, and serviceIf you need help, service, technical assistance, or want more information about IBMproducts, you can find various sources to assist you. You can view the followingwebsites to get information about IBM products and services and to find the latesttechnical information and support.v IBM website (ibm.com)v IBM Support Portal website (ibm.com/storage/support)v IBM Directory of Worldwide Contacts website (ibm.com/planetwide)v IBM service requests and PMRs (ibm.com/support/servicerequest/Home.action)

Use the Directory of Worldwide Contacts to find the appropriate phone number forinitiating voice call support. Voice calls arrive to Level 1 or Front Line Support.

Overview 19

http://www.ibm.com/systems/storage/disk/xiv

http://www.ibm.com/support/knowledgecenter/STJTAG

http://www.redbooks.ibm.com/portals/storage

http://www.ibm.com

http://www.ibm.com/storage/support

http://www.ibm.com/planetwide

http://www.ibm.com/support/servicerequest/Home.action


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Notices 23


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