Hi, Andersen The error message is saying that: a write request requires too many journal credits, it even exceeded the maximum credits for a single transaction (500), and we just turn to use the maximum value instead of calculated one (555). If there are lots write requests in parallel requires so much journal credits, the system could be easily running short of journal space, that'll cause performance drops since lot of requests have to wait on journal space. I guess the reason of write requiring so much credits is the write request contains many noncontiguous segments spreading over the file, it probably caused by some IO pattern changes of your application? Thanks - Niu On 3/6/13 3:31 AM, "Andersen, Per" <per.andersen(a)ttu.edu&gt; wrote: > We are running lustre 1.8.8 on centos 5.8 for the servers and the clients > are lustre 1.8.5 on centos 5.5. We have run trouble free with that setup > for over a year, the errors we are seeing now appeared in the last few > weeks and on only one OSS. I have goggled the error and found nothing > enlightening. > > Per Andersen Ph.D. P.E. > HPCC > Texas Tech University > 806-834-6924 > > > > -----Original Message----- > From: Jones, Peter A [mailto:peter.a.jones@intel.com] > Sent: Tuesday, March 05, 2013 1:01 PM > To: Andersen, Per; hpdd-discuss(a)lists.01.org > Subject: Re: [HPDD-discuss] Lustre error > > Per > > It would probably be helpful to know which release of Lustre that you are > running > > Peter > > On 3/5/13 6:25 AM, "Andersen, Per" > <per.andersen@ttu.edu<mailto:per.andersen@ttu.edu>> wrote: > > We started getting huge numbers of these messages on one of our OSS > servers, there are two OSS servers in the system each with 2 OSTs on > them. The second OSS does not generate these messages. > > Mar 5 08:20:20 rt-oss1 kernel: LustreError: > 29297:0:(fsfilt-ldiskfs.c:493:fsfilt_ldiskfs_brw_start()) want too many > journal credits (555) using 500 instead Mar 5 08:20:20 rt-oss1 kernel: > LustreError: 29297:0:(fsfilt-ldiskfs.c:493:fsfilt_ldiskfs_brw_start()) > Skipped 16215 previous similar messages > > Does anyone know what this message is about? Since we started getting > them the lustre system performance has been reduced. > > Per Andersen Ph.D. P.E. > HPCC > Texas Tech University > 806-834-6924 > > _______________________________________________ > HPDD-discuss mailing list > HPDD-discuss(a)lists.01.org > https://lists.01.org/mailman/listinfo/hpdd-discuss _______________________________________________ HPDD-discuss mailing list HPDD-discuss(a)lists.01.org https://lists.01.org/mailman/listinfo/hpdd-discuss