Re: bcache with existing ext4 filesystem

[Theodore Ts'o]

On Tue, Jul 25, 2017 at 03:46:04PM +0200, Pavel Machek wrote:
> 
> Is there some field in ext2 superblock that changes every time
> filesystem is changed? Is mtime changed by fsck/badblocks/...?

No, there isn't.  If we were writing the superblock every time the
file system is changed it would be ***extremely*** flash unfriendly.
It would also be a scalability bottleneck, it would cause us to pay an
extra HDD seek, etc.  So it's a really bad Bad BAD idea, and so we
don't do it.

Cheers,

					- Ted