Bug 2255435 - [RHCS 6] RFE: change default value of "mds_bal_interval" to "0", aka false
Summary: [RHCS 6] RFE: change default value of "mds_bal_interval" to "0", aka false
Keywords:
Status: CLOSED ERRATA
Alias: None
Product: Red Hat Ceph Storage
Classification: Red Hat Storage
Component: CephFS
Version: 5.3
Hardware: All
OS: All
unspecified
medium
Target Milestone: ---
: 6.1z4
Assignee: Patrick Donnelly
QA Contact: Hemanth Kumar
Disha Walvekar
URL:
Whiteboard:
Depends On: 2227309
Blocks: 2255436 2261930
TreeView+ depends on / blocked
 
Reported: 2023-12-20 18:33 UTC by Patrick Donnelly
Modified: 2024-06-02 02:28 UTC (History)
8 users (show)

Fixed In Version: ceph-17.2.6-187.el9cp
Doc Type: Enhancement
Doc Text:
Feature: MDS dynamic metadata balancer is off by default. Reason: Poor balancer behavior could fragment trees in undesirable or unintended ways simply by increasing the max_mds file system setting. Result: Operators must turn on the balancer explicitly to use it.
Clone Of:
Environment:
Last Closed: 2024-02-08 18:12:00 UTC
Embargoed:


Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
Ceph Project Bug Tracker 61378 0 None None None 2023-12-20 18:33:14 UTC
Red Hat Issue Tracker RHCEPH-8109 0 None None None 2023-12-20 18:33:40 UTC
Red Hat Knowledge Base (Solution) 7026124 0 None None None 2024-06-02 02:28:10 UTC
Red Hat Product Errata RHBA-2024:0747 0 None None None 2024-02-08 18:12:08 UTC

Description Patrick Donnelly 2023-12-20 18:33:14 UTC
This bug was initially created as a copy of Bug #2227309

I am copying this bug because: 

rhcs 6 config fix

Description of problem:  RFE: change default value of "mds_bal_interval" to "0", aka false

From case 03492882 and BZ (https://bugzilla.redhat.com/show_bug.cgi?id=2203258) we see that having "mds_bal_interval" enabled results in performance issue. Beyond the log evidence in BZ 2203258, the customer reports that Ceph FS latency has dropped by 75 percent and I/O in the cluster has doubled since "mds_bal_interval" was set to false on their system.

We'd like to see the change in 5.3z-whatever and 6.1z-whatever and beyond

See also KCS #7026124, (https://access.redhat.com/solutions/7026124)

This same customer commented if this feature hampers performance this much and there is no intention on fixing it, the default value should be changed.


Version-Release number of selected component (if applicable):


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Comment 9 errata-xmlrpc 2024-02-08 18:12:00 UTC
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory (Red Hat Ceph Storage 6.1 Bug Fix update), and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHBA-2024:0747


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