Re: Getting FS access events

Andreas Dilger
2001-05-14T18:02:21Z

Daniel writes:
> But we don't need anything so fancy to try out your idea, we just need
> a lvm-like device that can:
>
> - Maintain a block cache
> - Remap logical to physical blocks
> - Record the block accesses
> - Physically reorder the blocks according to the recorded order
> - Load a given region of disk into the block cache on command

The current LVM device (if compiled with DEBUG_MAP) will report all of
the logical->physical block mappings via printk. Probably too heavy-
weight for a large amount of IO. It could be changed to save the block
numbers into a cache, to be extracted later. All of the LVM mapping
is done in the lvm_map() function.

Cheers, Andreas
--
Andreas Dilger \ "If a man ate a pound of pasta and a pound of antipasto,
\ would they cancel out, leaving him still hungry?"
http://www-mddsp.enel.ucalgary.ca/People/adilger/ -- Dogbert