[dm-devel] [PATCH 1/6] dm cache: cache shrinking support

[Alasdair G Kergon]

On Mon, Nov 11, 2013 at 12:20:43PM -0500, Mike Snitzer wrote:
> From: Joe Thornber <ejt at redhat.com>
> 
> Allow a cache to shrink if the blocks being removed from the cache are
> not dirty.
 
Please would you document the intended procedure here?

> +			DMERR("unable to shrink cache due to dirty blocks");

This error is highly undesirable: part of a device has been removed
while it is still needed!

How does someone go about reducing the size of the cache avoiding this
error?  (Analogy: to reduce size of a filesystem you run a filesystem
resize process before reducing the size of the block device.)

Alasdair