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Documentation #6379

closed

Better document impact of putting journals on different disks

Added by David Moreau Simard over 10 years ago. Updated over 4 years ago.

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

0%

Tags:
Backport:
Reviewed:
Affected Versions:
Pull request ID:

Description

Questions such as the following are asked frequently on the mailing list and IRC:
- What happens if the journal is lost (the disk on which the journal is written to fails)
- How many OSD journals should you put on another disk
- What kind of performance increase should be expected by putting the journal on another disk

It seems recommended or at least implied that it is better to put the journals on different disks.
We should provide documentation to explain why and what are the possible drawbacks/consequences.

Ref:
http://ceph.com/docs/next/install/hardware-recommendations/#solid-state-drives
http://ceph.com/docs/next/rados/configuration/osd-config-ref/
http://ceph.com/community/ceph-performance-part-2-write-throughput-without-ssd-journals/
http://comments.gmane.org/gmane.comp.file-systems.ceph.user/4267
http://comments.gmane.org/gmane.comp.file-systems.ceph.user/3809

Actions #1

Updated by John Wilkins over 10 years ago

  • Assignee set to John Wilkins
Actions #2

Updated by Zac Dover over 4 years ago

  • Status changed from New to Closed

This bug has been judged too old to fix. This is because either it is either
1) raised against a version of Ceph prior to Luminous, or
2) just really old, and untouched for so long that it is unlikely nowadays to represent a live documentation concern.

If you think that the closing of this bug is an error, raise another bug of a similar kind. If you think that the matter requires urgent attention, please let Zac Dover know at .

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