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Support #36584

closed

OSD Anomaly behaviour in ceph-reweight

Added by JUan Galan over 5 years ago. Updated over 5 years ago.

Status:
Closed
Priority:
Normal
Assignee:
-
Category:
-
Target version:
-
% Done:

0%

Tags:
ceph-reweight
Reviewed:
Affected Versions:
Ceph - v10.2.5
Component(RADOS):
Pull request ID:

Description

ceph version 10.2.5

We have this behaviour with 2 OSDs in cluster making a backfilling bucle.

I'm executing this reweight

cn1.tf1msm1c1.cdn ~# ceph osd test-reweight-by-utilization 107 0.05 60
no change
moved 10 / 24576 (0.0406901%)
avg 61.1343
stddev 3.99152 -> 3.98466 (expected baseline 7.80911)
min osd.9 with 43 -> 43 pgs (0.703369 -> 0.703369 * mean)
max osd.36 with 66 -> 66 pgs (1.07959 -> 1.07959 * mean)

oload 107
max_change 0.05
max_change_osds 60
average 0.468249
overload 0.501027
osd.164 weight 0.830170 -> 0.880157

See attached file.

Thanks in advanced

Files

ceph_reweight.png (16.3 KB) ceph_reweight.png JUan Galan, 10/24/2018 10:59 AM
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 #1

Updated by Greg Farnum over 5 years ago

  • Project changed from Ceph to RADOS
  • Category deleted (OSD)
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 #2

Updated by Greg Farnum over 5 years ago

  • Tracker changed from Bug to Support
  • Status changed from New to Closed

Are you running the command repeatedly? reweight-by-utilization does not provide a stable balance; it's really just a "hotfix" workaround for extreme balance issues you are going to address in other ways more permanently.

Newer releases of Ceph include a balancer module in the manager that is designed to be stable and used in the long term.

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