[LUDOC-179] Document "dirdata" feature for upgraded filesystems Created: 03/Sep/13  Updated: 07/Oct/13  Resolved: 07/Oct/13

Status: Resolved
Project: Lustre Documentation
Component/s: None
Affects Version/s: None
Fix Version/s: None

Type: Bug Priority: Minor
Reporter: Andreas Dilger Assignee: nasf (Inactive)
Resolution: Duplicate Votes: 0
Labels: None

Severity: 3
Rank (Obsolete): 10053

 Description   

The dirdata feature should be enabled on MDT filesystems upgraded from 1.8 to 2.x using the command:

tune2fs -O dirdata /dev/{mdtdev}

This allows the FID data for each file to be stored in its directory entry and avoids a lookup of the FID in the Object Index. Without this change, the performance of accessing files is impacted significantly. The reason that this is not done automatically at upgrade time is twofold:

  • it can break the filesystem consistency if the filesystem is downgraded to 1.8 again and then upgraded a second time to 2.x
  • such actions should be controlled by the system administrator, since Lustre cannot determine itself whether the filesystem will need a downgrade to 1.8 again

We may consider for Lustre 2.6 (which will no longer be required to upgrade from 1.8 directly) to enable this feature automatically at mount time, but that should be addressed separately from documenting the current upgrade requirements.

 Comments   
Comment by nasf (Inactive) [ 07/Oct/13 ]

The work is already in processing under LUDOC-68

Generated at Sat Feb 10 03:40:52 UTC 2024 using Jira 9.4.14#940014-sha1:734e6822bbf0d45eff9af51f82432957f73aa32c.