A fix is available
APAR status
Closed as new function.
Error description
This apar will provide new zFS High Availability support.
Local fix
Problem summary
**************************************************************** * USERS AFFECTED: * * zFS Version 2 Release 3 * * zFS FMID:HZFS430 * * * * zFS Version 2 Release 4 * * zFS FMID:HZFS440 * **************************************************************** * PROBLEM DESCRIPTION: * * APAR OA57508 enables the high * * availability function on V2R3 and V2R4 * * systems. With the PTF applied on all * * V2R3 and V2R4 systems, you can take * * advantage of the zFS high availability * * support on those systems. * **************************************************************** * RECOMMENDATION: * * APPLY PTF * **************************************************************** With the zFS high availability option, if the file system owner experiences an outage, applications that are accessing file systems on other systems are not affected. You can use a mount parameter or the IOEFSPRM option to designate a zFS sysplex-aware file system as high availability. To take advantage of the zFS high availability support, apply the PTF for APAR OA57508 on all V2R3 and V2R4 systems. For read/write sysplex-aware file systems, consider whether they should be high availability. If you are concerned about application availability after a system experiences an outage, consider using the high availability option.
Problem conclusion
APAR OA57508 enables the high availability function on V2R3 and V2R4 systems. With the PTF applied on all V2R3 and V2R4 systems, you can take advantage of the zFS high availability support on those systems. Updates are provided for the the following books : z/OS Version 2 Release 3 Distributed File System Administration SC23-6887-30 z/OS Version 2 Release 3 Distributed File Service Messages and Codes SC23-6885-30 z/OS Version 2 Release 4 File System Administration SC23-6887-40 The following information is being added to the z/OS Version 2 Release 3 Distributed File System Administration book: The z/OS Version 2 Release 3 Distributed File System Administration and Messages and Code updates can also be found at the following url: http://publibz.boulder.ibm.com/zoslib/pdf/OA57508.pdf In the Summary of changes , the following is being added: The high availability option With the zFS high availability option, if the file system owner experiences an outage, applications that are accessing file systems on other systems are not affected. You can use a mount parameter or the IOEFSPRM option to designate a zFS sysplex-aware file system as high availability. To take advantage of the zFS high availability support, apply the PTF for APAR OA57508 on all V2R3 and V2R4 systems. For read/write sysplex-aware file systems, consider whether they should be high availability. If you are concerned about application availability after a system experiences an outage, consider using the high availability option. In Chapter 4. Creating and managing zFS file systems using compatibility mode aggregates The following information is being added in Changing zFS attributes on a mounted zFS compatibility mode file system: zFS attributes are assigned to a zFS compatibility mode file system when it is mounted. The attributes can be set by specifying a zFS MOUNT parameter or they can be set from the zFS default values of the system where the primary mount occurs. These attributes, which are generally only meaningful for read/write mounted file systems, include HA. You can query the current default value of a zFS attribute by issuing the zfsadm configquery command. For example, to query the default value of the following attributes, issue the following command: zfsadm configquery -ha Also, as the following example shows, you can change the zFS default values by issuing the zfsadm config command: zfsadm config -ha on Specifying the high availability option for read/write sysplex-aware file systems With the zFS high availability option, if the file system owner experiences an outage, applications from other systems that are accessing that particular file system are not affected. File systems such as WebSphere Application Server and CICS that do not make frequent directory operations from non-owning systems might find the high availability option useful. To designate a zFS file system as high availability, you have two choices: - Specify the HA option in the MOUNT parameter of the BPXPRMxx parmlib member. - Use the HA=ON option in the IOEFSPRM file. To dynamically enable or disable the high availability function for a file system, use the zfsadm chaggr command. Important: Do not use the HA option or have the IOEFSPRM option default to ON unless all sysplex members have the PTF for APAR OA57508 applied. Usage notes: 1. You cannot use the high availability option if there are systems in the sysplex that do not have the PTF for APAR OA57508 applied. Even if the IOEFSPRM HA option is set so that high availability is enabled by default or if HA is specified in the mount parameter, zFS will still consider the file system to be non-high availability. 2. If a high availability file system is mounted in the sysplex, systems in the sysplex that do not have the PTF for APAR OA57508 applied will not be allowed to initialize. If those systems must be initialized, you will have to either unmount the high availability file systems or use the zfsadm chaggr command to remove the high availability option from the file systems. The zfsadm fsinfo command can be used to determine which file systems are mounted with the high availability option. 3. In a high availability file system, applications that are creating or updating files will not see errors if the owning system goes down. However, if the application is working with a FIFO special file, it will see errors if the owning system goes down. 4. To ensure that applications do not receive errors, use the high availability option when you are mounting any file system that is accessed by applications in a parallel sysplex. Also, include the file systems that are at a higher level in the mount tree. The high availability option is not needed for file systems that are mounted read-only. 5. The high availability option is not needed for file systems that are mounted with the noautomove and unmount automove options. Those file systems cannot be accessed by other systems if the owning system is terminated. 6. If the high availability option is used, disk synchronization of the internal log file in the file system occurs more often. An increase in the response time of metadata (any file system data that is not the contents of user files) operations for requests from sysplex client systems will occur. Applications on the owning system do not need to synchronize the log file. However, because the log file is shared, workloads that frequently update the directories from non-owning systems of the file system will experience slower performance on both the client systems and the owning system. If performance is critical, the high availability option might not be a good choice. In Chapter 11. zFS commands The MOUNT command section is being updated to include: The HA | NOHA options were added to the MOUNT command. HA | NOHA Specifies whether the system will provide high availability for applications on non-owning systems for a sysplex-aware file system when the owning system experiences an outage. The default is the HA specification in the IOEFSPRM file. Using the HA mount option increases the directory response time from non-owning systems. The zfsadm chaggr command section is being updated to include: zfsadm chaggr The -ha | -noha options were added to the zfsadm chaggr command. -ha | -noha Specifies whether the aggregate should provide the high availability. The -ha and -noha options will cause a samemode remount to be issued if the aggregate is mounted read/write. If the aggregate is mounted read-only, only the mount parameters are updated. The -ha and -noha options are mutually exclusive. The zfsadm chaggr command section is being updated to include: zfsadm config The -ha option was added to the zfsadm config command. -ha ON | OFF Specifies whether the high availability option is enabled by default for mounts of sysplex-aware file systems. The zfsadm configquery command section is being updated to include: zfsadm configquery The -ha option was added to the zfsadm configquery command. -ha Displays whether the high availability option is enabled by default for mounts of sysplex-aware file systems. The zfsadm fsinfo command section is being updated to include: zfsadm fsinfo Aggregates can be selected by use of the -select option. HA and NOHA were added to the list of criteria for selecting aggregates. HA shows aggregates that are mounted with the high availability option. NOHA shows aggregates that are not mounted with the high availability option. When you use the -owner option, the displayed information has the file system status as part of the output. HA indicates that the aggregate is mounted with the high availability option. In Chapter 12. The zFS configuration options file (IOEPRMxx or IOEFSPRM). the following information is being added: IOEFSPRM HA Specifies whether high availability is enabled by default for mounts of sysplex-aware file systems. The expected value is ON or OFF. For example: HA = ON The default value is OFF. In Chapter 13. zFS application programming interface information, the following information is being added: pfsctl (BPX1PCT) Two subcommands (opcodes) were added: Query HA and Set HA. For Command Subcommands(opcodes) Configuration ZFSCALL_CONFIG Query HA (269) (0x40000006) For Command Subcommands(opcodes) Configuration ZFSCALL_CONFIG Set HA (268) (0x40000006) Change Aggregate Attributes The ch_ha_flags attribute was added. ch_ha_flags char Indicates if aggregate should be high availability. 1 - File system should be high availability. 2 - File system should not be high availability. List Detailed File System Information For fr_selection, these lines were added: x20000000 - Show aggregates that are high availability. x40000000 - Show aggregates that are not high availability. In the z/OS Version 2 Release 3 Distributed File Service Messages and Codes (SC23-6885-30), the following messages are being added: IOEZ01028E Unexpected errors during takeover processing for HA file system filesystem_name with new owner system_name. Explanation zFS encountered unexpected errors while resolving pending operations that were in progress when the original owner of the file system went down. This means the applications that requested those operations will receive EIO (122) errors from zFS. In the message text: filesystem_name The name of the file system. system_name The name of the system. System action The program continues. Severity svc_c_sev_error Administrator Response Contact your service representative. IOEZ01029E The HA attribute is not assigned to file system filesystem_name because system system_name does not support high availability file systems. Explanation The HA attribute was to be assigned to the specified file system either because the HA mount parameter was specified or the IOEFSPRM configuration option HA=ON is specified. The HA attribute can only be used when all members of a sysplex support high availability file systems. In the message text: file_system The name of the file system. system_name The name of the system that does not support high availability file systems. System action The program continues. Severity svc_c_sev_error Administrator Response To use the HA file system attribute, ensure that all members in the sysplex have OA57508 applied. Then you can enable the HA attribute for this file system by using the zfsadm chaggr command with the -ha option. Alternatively, you could unmount the file system, and mount it again with the HA mount parameter. Or, you can issue the zfsadm config command with -ha on specified, then unmount and mount the file system again. IOEZ01030E Initializing system system_name will not be allowed to join the sysplex because it does not support high availability file systems. Explanation There is at least one high availability (HA) mounted file system in the sysplex. HA support requires that all members of a sysplex support HA. In the message text: system_name Name of the initializing system that does not support HA. System action The program continues. Severity svc_c_sev_warning Administrator Response zFS on the initializing system will terminate. To correct this problem, either unmount or change the HA status of all file systems that are currently mounted HA. The zfsadm chaggr command can be used to change the HA status of a file system. The following reason codes have been added: Reason codes 6CA0 A sysplex client without high availability mount support (HA) is trying to connect to an HA-mounted file system. Action: Retry the operation when the client system is at a level that supports high availability mount. 6CA2 An invalid value was specified for the -ha aggregate attribute. Action: The -ha aggregate attribute takes a value of either ON or OFF. When using the Change Aggregate Attributes API, use the corresponding value, which is either 1 (for ON) or 2 (for OFF). 6CA3 The aggregate attribute cannot be changed to both -ha and -noha. Action: Limit your request to one attribute value and try again. 6CA5 The HA aggregate attribute cannot be used in a sysplex where some systems do not support high availability file systems. Action: Ensure that APAR OA57508 is applied to all systems in the sysplex and try the command again. The following information is being updated in z/OS Version 2 Release 4 File System Administration SC23-6887-40: In Chapter 5. Using zFS in a shared file system environment in the section: Specifying the high availability option for read/write sysplex-aware filesystems The following is being updated: High availability option for read/write sysplex-aware file systems With the zFS high availability option, if the file system owner experiences an outage, applications from other systems that are accessing that particular file system are not affected. File systems such as WebSphere Application Server and CICS that do not make frequent directory operations from non-owning systems might find the high availability option useful. To designate a zFS file system as high availability, you have two choices: Specify the HA option in the MOUNT parameter of the BPXPRMxx parmlib member. See zfsmount - Mount a file system into the z/OS UNIX hierarchy MOUNT. Use the HA=ON option in the IOEFSPRM file. See IOEFSPRM. To dynamically enable or disable the high availability function for a file system, use the zfsadm chaggr command. See zfsadmchaggr - Changes the attributes of an aggregatezfsadm chaggr. Important: Do not use the HA option or have the IOEFSPRM option default to ON unless all sysplex members are at the 2.4 level or at the 2.3 level with APAR OA57508 applied. Usage notes: 1. You cannot use the high availability option if there are systems in the sysplex that are not at the 2.4 level or at the 2.3 level with APAR OA57508 applied. Even if the IOEFSPRM HA option is set so that high availability is enabled by default and if HA is specified in the mount parameter, zFS will still consider the file system to be non-high availability. 2. If a high availability file system is mounted in the sysplex, be aware that systems in the sysplex that are not at the 2.4 level or at the 2.3 level with APAR OA57508 applied are not allowed to initialize. If those systems must be initialized, you will have to either unmount the high availability file systems or use the zfsadm chaggr command to remove the high availability option from the file systems. The zfsadm fsinfo command can be used to determine which file systems are mounted with the high availability option. 3. In a high availability file system, applications that are creating or updating files will not see errors if the owning system goes down. However, if the application is working with a FIFO special file, it will see errors if the owning system goes down. 4. To ensure that applications do not receive errors, use the high availability option when you are mounting any file system that is accessed by applications in a parallel sysplex. Also, include the file systems in a higher level in the mount tree. The high availability option is not needed for file systems that are mounted read-only. 5. The high availability option is not needed for file systems that are mounted with the noautomove and unmount automove options. Those file systems are not accessed by other systems if the owning system is terminated. 6. If the high availability option is used, disk synchronization of the internal log file in the file system occurs more often. An increase in the response time of metadata (any file system data that is not the contents of user files) operations for requests from sysplex client systems will occur. Applications on the owning system do not need to synchronize the log file. However, because the log file is shared, workloads that frequently update the directories from non-owning systems of the file system will experience slower performance on both the client systems and the owning system. If performance is critical, the high availability option might not be a good choice. After the activation of OA57508, the following messages may be generated: IOEZ01028E IOEZ01029E IOEZ01030E
Temporary fix
Comments
APAR Information
APAR number
OA57508
Reported component name
ZFS ZSERIES FIL
Reported component ID
5696EFS00
Reported release
440
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
YesSpecatt / New Function / Xsystem
Submitted date
2019-05-07
Closed date
2019-12-12
Last modified date
2020-01-03
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
UJ01635 UJ01636
Modules/Macros
IOEFSUTL IOEZHADD IOEZHMSG IOEZADM IOEDUMPF IOEFSCM IOEFSTHD IOEZHCK1 IOEFSKN IOEAGFMT IOEAGSLV
| SC23688730 | SC23688740 | SC23688530 |
Fix information
Fixed component name
ZFS ZSERIES FIL
Fixed component ID
5696EFS00
Applicable component levels
Fix is available
Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.
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Document Information
Modified date:
03 January 2020