Re: [linux-lvm] [PATCH] Fix for hanging resize on root filesystem

[Alasdair G Kergon <agk redhat com>]

On Fri, Sep 10, 2004 at 08:47:24AM -0400, Jeff Mahoney wrote:
> When a user has their root filesystem on an LV and attempts to resize
> the LV, the kernel will deadlock while trying to update the atime on the
> device node.
 
Indeed, and if you push harder you'll probably find some trickier
problems there too.  This is one of the reasons I've said numerous
times we don't support pvmove/snapshots of the devices used by the
tools themselves.  I shall add a test to the tools to detect when
people do this.  [See also the old 2.4 kernel patch included in the
source tree (but not applied by default) which disables the relevant
*time updates - write as well as read. I've not had time to look at 
equivalents for 2.6 yet.]

The way I envisage snapshots/pvmoves being supported most safely 
is by using temporary copies of the relevant inodes on a filesystem
that does not get suspended.

Alasdair
-- 
agk redhat com