[LU-1885] Lustre should be able to limit amount of memory used for read and write caches

• Status: Resolved
• Project: Lustre
• Type: New Feature
• Priority: Minor
• Reporter: Shuichi Ihara (Inactive)
• Assignee: Peter Jones
• Resolution: Won't Fix

Description

This has been discussed before, but I couldn't find any bugs or mailing list threads that specifically dealt with it, so I thought I'd open up a formal feature request. Basically we would like to use the read and write caches, but don't want them to take up all the memory. We'd like to be able to keep a large amount of memory available for the block bitmaps and other OST ext metadata, without having to pin everything in memory with vfs_cache_pressure=0.

How much control is there in the Linux page cache? Is it possible to tell it to start flushing the object caches if they start taking up X amount of space?

Issue Links

• is related to: LU-10967 MDT page cache management improvements

Comments

[Kit Westneat (Inactive)]

or alternatively if it could prioritize it so the cache flushes objects before metadata, that would have the same desired effect.

[Peter Jones]

thanks for the suggestion Kit. I'll raise this suggestion when we start the next round of planning

[John Fuchs-Chesney (Inactive)]

Do we want to keep this ticket open?

Thanks,
~ jfc.

[Peter Jones]

Closing out of date ticket