[LU-13691] Allow for lfs migrate between MDTs to include DOM

• Status: Open
• Project: Lustre
• Type: Improvement
• Priority: Minor
• Reporter: Kyle Lamb (Inactive)
• Assignee: Lai Siyao
• Resolution: Unresolved
• Epic/Theme: dne

Description

Would it be possible to add options to allow lfs migrate to be used for migration of files/directories between MDTs to include DOM data partitions?  For example directoryA has files with inodes and a DOM layout on MDT00.  Lfs migrate directoryA to MDT01 such that both inodes and DOM components are migrated. 

 

Would it be possible to have data beyond the MDT remain in place on OSTs?  

 

Issue Links

• is related to: LU-13298 lfs migrate -m "migrate failed: Opera...
• is related to: LU-11025 DNE3: directory restripe

Comments

[Andreas Dilger]

Mike, and Lai, could you please provide some input on how easy or hard this would be to implement.

This is similar to DNE directory migration, but would also move the DoM data. I believe that it is possible to create FLR mirrors of DoM files today, but this keeps the same inode on the MDT. AFAIK, it is not possible to migrate the inode with DoM to a different MDT at the same time, but maybe that was implemented in 2.14?

[Lai Siyao]

In the last patch of LU-11025, if it's DoM file, migration will migrate dirent, and leave inode untouched, instead of return -EOPNOTSUPP.