Re: [Xen-users] Trim support for domU

[Liwei <xieliwei@xxxxxxxxx>]

On 9 July 2012 11:42, Casey DeLorme <cdelorme@xxxxxxxxx> wrote:
> I have been using a SSD with Xen 4.2 for 6 months.  I am running on Debian
> Wheezy Dom0, and a compiled Kernel 3.4.4.
>
> Trim required not only the appropriate kernel, but the discard flag in
> fstab, and only for compatible file systems (Ext4 being one).
>
> My SSD has /boot/efi and /boot partitions, the rest is LVM, and I have Ext4
> for my /home and / (root) partitions with discard flag added manually to
> /etc/fstab.  This appears to be working.
>
> For virtual machines I have an HVM Windows which without GPLPV drivers
> appears to have recognized that it was running on a SSD (well a LV on an
> SSD), as it had Auto Disk Defrag turned off.  So HVM Windows appears to
> support trim.
>
> I have been running a Debian Squeeze HVM DomU for web development testing,
> and for stability I had not added trim.  I also have been running a pfSense
> HVM DomU (FreeBSD) but I have not checked whether it supports trim either.
>

Thanks for the reply, it sure increases the optimism in me! I'll give
it a try with today's xen-unstable and mainline kernel.

However, can any dev clarify how trim could work on non-PV machines,
and even on LVM? My original impression was that it'd only be remotely
possible by passing in the whole SSD, but Casey seems to have it
working on a LVM volume on an SSD. Thanks!

_______________________________________________
Xen-users mailing list
Xen-users@xxxxxxxxxxxxx
http://lists.xen.org/xen-users