Flashes (Alerts)
Abstract
APAR HU02141 may cause multiple node warmstarts and a loss of access, on systems which are using Global Mirror and the max replication delay feature.
This issue affects systems running 8.1.0.0-8.2.1.10 or 8.3.0.x software.
Content
Global Mirror users can specify a maximum permissible delay time for a single I/O, using the max replication delay feature.
APAR HU02141 is a software issue that can cause all nodes to warmstart, if this feature is enabled and multiple I/O requests are delayed at the same time.
This feature is disabled by default. To identify whether max replication delay has been enabled, run the following CLI command:
lssystem |grep max_replication_delay
If max_replication_delay is non-zero, then the feature is enabled.
Workaround
This issue is most likely to be seen during maintenance actions (for example, on the inter-cluster link, or on a node). If performing maintenance, temporarily disable max replication delay beforehand. Doing so will prevent the maintenance action from triggering this software issue.
To disable the feature, run the following CLI command:
chsystem -maxreplicationdelay 0
If maintenance is not being performed, it is still possible for the issue to be triggered if delays happen for some other reason. Disabling the max replication delay feature will prevent this issue, but will also disable protection against a single host write taking a long time to complete.
Fix
Upgrade systems using Global Mirror with max replication delay to 8.2.1.11, or to 8.3.1.0 or later.
Once the upgrade has been completed, re-enable max replication delay if you previously disabled it.
[{"Business Unit":{"code":"BU058","label":"IBM Infrastructure w\/TPS"},"Product":{"code":"ST3FR7","label":"IBM Storwize V7000"},"Component":"","Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"All Versions","Edition":"","Line of Business":{"code":"LOB26","label":"Storage"}},{"Business Unit":{"code":"BU058","label":"IBM Infrastructure w\/TPS"},"Product":{"code":"STPVGU","label":"SAN Volume Controller"},"Component":"","Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"All Versions","Edition":"","Line of Business":{"code":"LOB26","label":"Storage"}},{"Business Unit":{"code":"BU058","label":"IBM Infrastructure w\/TPS"},"Product":{"code":"STHGUJ","label":"IBM Storwize V5000"},"Component":"","Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"All Versions","Edition":"","Line of Business":{"code":"LOB26","label":"Storage"}},{"Business Unit":{"code":"BU054","label":"Systems w\/TPS"},"Product":{"code":"STKMQV","label":"IBM FlashSystem V9000"},"Component":"","Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"All Versions","Edition":"","Line of Business":{"code":"LOB26","label":"Storage"}},{"Business Unit":{"code":"BU058","label":"IBM Infrastructure w\/TPS"},"Product":{"code":"STSLR9","label":"IBM FlashSystem 9x00"},"Component":"","Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"All Versions","Edition":"","Line of Business":{"code":"LOB26","label":"Storage"}},{"Business Unit":{"code":"BU058","label":"IBM Infrastructure w\/TPS"},"Product":{"code":"STSLR9","label":"IBM FlashSystem 9x00"},"ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"All Version(s)","Line of Business":{"code":"LOB26","label":"Storage"}},{"Business Unit":{"code":"BU058","label":"IBM Infrastructure w\/TPS"},"Product":{"code":"SSA76Z4","label":"IBM FlashSystem 7x00"},"ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"All Version(s)","Line of Business":{"code":"LOB26","label":"Storage"}},{"Business Unit":{"code":"BU058","label":"IBM Infrastructure w\/TPS"},"Product":{"code":"STHGUL","label":"IBM Storwize V5000E"},"ARM Category":[{"code":"a8m0z000000bqPRAAY","label":"Configuration"}],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"All Version(s)","Line of Business":{"code":"LOB26","label":"Storage"}}]
Was this topic helpful?
Document Information
Modified date:
28 March 2023
UID
ibm16257827