Yes, we run mmbackup, using a snapshot. The scan usally takes an hour, but for the last week has been taking many hours (i saw it take 12 last Tuesday)
It's speeded up again now back to its normal hour, but the high io jobs accessing the same file from many nodes also look to have come to an end for the time being. I was trying to figure out howto control the bad io using mmchqos, to prioritise certain nodes over others but had not worked out if that was possible yet. We've only previously seen this problem when we had some bad disks in our storage, which we replaced, I've checked and I can't see that issue currently. Thanks for the help. Peter Childs Research Storage ITS Research and Teaching Support Queen Mary, University of London ---- Yaron Daniel wrote ---- Hi Do u run mmbackup on snapshot , which is read only ? Regards ________________________________ Yaron Daniel 94 Em Ha'Moshavot Rd [cid:_1_0C9372140C936C60006FF189C22582D1] Storage Architect – IL Lab Services (Storage) Petach Tiqva, 49527 IBM Global Markets, Systems HW Sales Israel Phone: +972-3-916-5672 Fax: +972-3-916-5672 Mobile: +972-52-8395593 e-mail: [email protected] IBM Israel<http://www.ibm.com/il/he/> [IBM Storage Strategy and Solutions v1][IBM Storage Management and Data Protection v1][cid:_1_0C9306EC0C92FECC006FF189C22582D1][cid:_1_0C9308F40C92FECC006FF189C22582D1] [https://acclaim-production-app.s3.amazonaws.com/images/6c2c3858-6df8-45be-ac2b-f93b8da74e20/Data%2BDriven%2BMulti%2BCloud%2BStrategy%2BV1%2Bver%2B4.png] [Related image] From: Peter Childs <[email protected]> To: "[email protected]" <[email protected]> Date: 07/10/2018 05:51 PM Subject: [gpfsug-discuss] Same file opened by many nodes / processes Sent by: [email protected] ________________________________ We have an situation where the same file is being read by around 5000 "jobs" this is an array job in uge with a tc set, so the file in question is being opened by about 100 processes/jobs at the same time. Its a ~200GB file so copying the file locally first is not an easy answer, and these jobs are causing issues with mmbackup scanning the file system, in that the scan is taking 3 hours instead of the normal 40-60 minutes. This is read only access to the file, I don't know the specifics about the job. It looks like the metanode is moving around a fair amount (given what I can see from mmfsadm saferdump file) I'm wondering if we there is anything we can do to improve things or that can be tuned within GPFS, I'm don't think we have an issue with token management, but would increasing maxFileToCache on our token manager node help say? Is there anything else I should look at, to try and attempt to allow GPFS to share this file better. Thanks in advance Peter Childs -- Peter Childs ITS Research Storage Queen Mary, University of London _______________________________________________ gpfsug-discuss mailing list gpfsug-discuss at spectrumscale.org http://gpfsug.org/mailman/listinfo/gpfsug-discuss
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