one final word of warning for everyone. while i no longer have the performance glitch.... I can no longer reproduce it. Doing ceph config set global rbd_cache true does not seem to reproduce the old behaviour. even if i do things like unmap and remap the test rbd. Which is worrying. because if I cant control the behaviour.... who is to say it wont mysteriously come back? ----- Original Message ----- From: "Philip Brown" <pbrown@xxxxxxxxxx> To: "Sebastian Trojanowski" <sebcio.t@xxxxxxxxx> Cc: "ceph-users" <ceph-users@xxxxxxx> Sent: Thursday, December 17, 2020 9:02:05 AM Subject: Re: Re: performance degredation every 30 seconds I am happy to say, this seems to have been the solution. After running ceph config set global rbd_cache false I can now run the full 256 thread varient, fio --direct=1 --rw=randwrite --bs=4k --ioengine=libaio --filename=/dev/rbd0 --iodepth=256 --numjobs=1 --time_based --group_reporting --name=iops-test-job --runtime=120 --eta-newline=1 and there is no longer a noticeable performance dip. Thanks Sebastian _______________________________________________ ceph-users mailing list -- ceph-users@xxxxxxx To unsubscribe send an email to ceph-users-leave@xxxxxxx
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