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Bug #14117
closedKRBD : Performance issues with kernel 4.1 series
% Done:
0%
Source:
other
Tags:
Backport:
Regression:
No
Severity:
3 - minor
Reviewed:
Affected Versions:
ceph-qa-suite:
Crash signature (v1):
Crash signature (v2):
Description
I am finding that it is a specific client that is experiencing this issue. Doing an RBD write from another client has no problem and OK throughput:
rbd map spin1/rbdtest
/dev/rbd0
root@lab2-mon1:/usr/local/ISS/supercore/temp/operations# dd if=/dev/zero of=/dev/rbd0 bs=1M count=1000
1000+0 records in
1000+0 records out
1048576000 bytes (1.0 GB) copied, 4.36296 s, 240 MB/s
Versus
root@e1:~# dd if=/dev/zero of=/dev/rbd0 bs=1M count=1000
1000+0 records in
1000+0 records out
1048576000 bytes (1.0 GB) copied, 46.3618 s, 22.6 MB/s
This problem looks like in kernel with 4.1 series :
kernel 4.1.6 is slow
kernel 4.1.15 is slow
As it is good with:
kernel 3.19 is fast
kernel 4.2.8 is fast
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