5:26 p.m.
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> 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