Re: file corruption problems (!) in a xen domU backed by a zvol

[Greg Troxel <gdt%lexort.com@localhost>]

Jeff Rizzo <riz%tastylime.net@localhost> writes:

> The host has a NetBSD 10.1 kernel and a 9.0 userland that's in the
> process of being updated to 10.1 - unpacking `base.tar.xz` is where I
> first noticed problems. Here's a quick summary of the problem in
> example form:
>
> ansible:riz  ~/sets> md5 xfont.tar.xz
> MD5 (xfont.tar.xz) = f044efd355a3a8fbee8988200aa526d5
> ansible:riz  ~/sets> md5 xfont.tar.xz
> MD5 (xfont.tar.xz) = 07e28b41bb982b2b0a1e0b731599a246
> ansible:riz  ~/sets> md5 xfont.tar.xz
> MD5 (xfont.tar.xz) = b0d14f58745706db4dcf4a30d5b75175
> ansible:riz  ~/sets>

Are you saying that in a domU you are running md5, and the file is in
UFS on an xbd, and the xbd is backed by a zvol in the dom0?

I would suggest that you boot the domU single user and repeat this, and
also md5 or sha1 the zvol.

I have 5 domUs  of various netbsd version/arch where the xbd or wd (soem
HVM, some PV, some PVH) is backed by a zvol.   My dom0 is netbsd-10 and
the zpool has one disk only.  I have not seen any flakiness like this.

(zfs does lock up when writing mmmaped files under memory pressure, but
that's different)



I wonder if you have troubled memory and suggest running memory
diagnostics on the box.