We deeply regret to inform GPFS users that the 126.96.36.199 service update contains a serious flaw. When parsing some RPCs sent by nodes running GPFS 188.8.131.52 or earlier, the code in 184.108.40.206 incorrectly processes certain data structures, resulting in GPFS crashes. The most typical symptom of this issue is the "((diskNum > 0) && (diskNum <= sgP->getNDisks())" assert in LogFile::append, although other symptoms are possible. The problem occurs most readily when metadata is not replicated (mmlsfs shows -m 1); metadata replication mitigates the problem to a large extent, but not completely. Full data and metadata replication would prevent the problem from happening.
The problem is limited to the scenarios where 220.127.116.11 and pre-18.104.22.168 nodes are present in the same cluster, accessing the same file systems. If you are considering upgrading GPFS from a pre-22.214.171.124 level (including 3.3.0.X), do not upgrade to the unpatched 126.96.36.199. Clusters running only 188.8.131.52 or later nodes, including 184.108.40.206, are not affected.
The problem will be fixed in 220.127.116.11. An efix for 18.104.22.168 is also available via IBM Service.
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1 reply Latest Post - 2012-05-02T18:48:32Z by firstname.lastname@example.org
Pinned topic Backward compatibility problem in GPFS 22.214.171.124
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Updated on 2012-05-02T18:48:32Z at 2012-05-02T18:48:32Z by email@example.com
firstname.lastname@example.org 060000T9GF209 PostsACCEPTED ANSWER
Re: Backward compatibility problem in GPFS 126.96.36.199012-05-02T18:48:32Z in response to email@example.comTo expand on the previous post: both 188.8.131.52 and 184.108.40.206 levels contain the same backward compatibility issue. All of the 220.127.116.11 warnings and workarounds also apply to 18.104.22.168.