Re: Xen 3.0.3 tap:aio disk image fails on RAID5/XFS filesystem

[Steven Haigh <netwiz@crc.id.au>]

On Tue, 27 Apr 2010 12:00:54 +0300, Pasi Kärkkäinen <pasik@iki.fi> wrote:
> On Tue, Apr 27, 2010 at 05:19:54PM +1000, Steven Haigh wrote:
>> 
>> On Tue, 27 Apr 2010 14:01:17 +1000, Steven Haigh <netwiz@crc.id.au>
>> wrote:
>> > Hi all,
>> > 
>> > Upon bashing my head against a wall trying to get Xen working on my
new
>> > hardware I came across an interesting discovery. Every install using
>> > virt-install was failing and I could only use the file: access method
>> for
>> > my DomUs. Every time I tries to use tap:aio the guest would error on
>> boot
>> > saying it couldn't find the root partition.
>> > 
>> > My system is as follows:
>> > OS: CentOS 5.4
>> > Xen: 3.0.3-94.el5_4.3
>> > / = 2 x 80Gb HDDs, dmraid1, ext3
>> > /mnt/raid = 3 x 1Tb HDDs, dmraid5, xfs
>> > 
>> > On whim, I moved the DomU images from /mnt/raid/vm-images to
/vm-images
>> > and instantly tap:aio worked again.
>> > 
>> > This brings me to my question:
>> > 
>> > Why would tap:aio fail when the images are on an XFS/RAID5 filesystem
>> but
>> > work correctly when on a RAID1/ext3 filesystem?
>> > 
>> > To me, this seems like a bug.
>> 
>> Oh, and for the record, this is my config file:
>> 
>> name = "mail.crc.id.au"
>> uuid = "929c5a29-10c2-b388-ff01-42110c4ea66e"
>> maxmem = 512
>> memory = 512
>> vcpus = 2
>> bootloader = "/usr/bin/pygrub"
>> on_poweroff = "destroy"
>> on_reboot = "restart"
>> on_crash = "restart"
>> #disk = [ "file:/vm-images/mail.crc.id.au.img,xvda,w" ]
>> disk = [ "tap:aio:/vm-images/mail.crc.id.au.img,xvda,w" ]
>> vif = [ "mac=00:16:3E:00:00:13, bridge=virbr0" ]
>> 
> 
> Since you're using EL5 distribution you might want to search Redhat
> bugzilla
> to see if there are already existing bugreports about this issue.
> 

I did have a hunt around - but I couldn't locate anything relevant - hence
my post here to see if it is anything that is already known - and maybe
documented somewhere...

-- 
Steven Haigh
 
Email: netwiz@crc.id.au
Web: http://www.crc.id.au
Phone: (03) 9001 6090 - 0412 935 897
Fax: (03) 8338 0299