Re: [Xen-users] tap:aio not working...

[Marcel Ritter <Marcel.Ritter@xxxxxxxxxxxxxxxxxxxx>]

Gernot Kieseritzky schrieb:
> Hi!
>
>   
> > Nick Couchman schrieb:
> >     
> > > > I'm running SLES10 SP1 and have been using file:/ for my file-backed domUs.  
> > > > The domUs sit on a shared OCFS2 SAN-backed filesystem and are run on my three 
> > > > or four XEN servers.  I'm having issues with the loopback devices not being 
> > > > released when the domUs shutdown or migrate, so I decided to switch over to 
> > > > tap:aio for my file-backed domUs.  This isn't working, either.  Whereas the 
> > > > domUs with file: at least boot and run, the domUs with tap:aio: fail with this 
> > > > error:
> > > >  
> > > >   
> > > >         
> > Hi Nick,
> >
> > we're running quite some Xen machines on SLES 10 SP1 here, too.
> > I tried to switch from file:/ to tap:aio:/ (as xen documentation 
> > recommends),
> > without success. As far as I can see the creation itself works, but it locks
> > down the machine shortly after accessing it.
> >
> > For now I do my testing on Dom0 (it's easier to see what's happening there).
> > So here's what I tried:
> >
> > # Create 2 TB sparse file
> > linux # dd if=/dev/zero of=/proj.stand/xen/disk2 bs=1M count=1 seek=2048000
> > 1+0 records in
> > 1+0 records out
> > 1048576 bytes (1,0 MB) copied, 0,018314 seconds, 57,3 MB/s
> >
> > # Attach it to dom0 as /dev/hdb
> > linux # xm block-attach 0 tap:aio:/proj.stand/xen/disk2 /dev/hdb  w 0
> > linux # cat /proc/partitions
> > ...
> >    3    64 2097153024 hdb
> > ...
> >
> > Now fdisk/mount this device - whatever you like.
> >
> > During my test the machine froze quite fast, however the same tests with 
> > file:/
> > work quite well - no idea why.
> >
> > Someone on the list, where this works?
> >     
> Have you checked that the process "blktapctrl" is running on dom0 (ps ax
> | grep blktapctrl)? If not, than your Kernel might be compiled without
> blktap support. I'm using Xen with Debian-Etch in dom0 and the debian
> xen-kernel has blktap-support disabled by default so I had to build a
> custom kernel.
>
>   
Yepp, should be compiled in: process is running, modules loaded:

linux7:~ # ps -ef | grep blkta
root 3735 1 0 Apr23 ? 00:00:00 blktapctrl
root 15395 15326 0 13:34 pts/9 00:00:00 grep blkta
linux7:~ # lsmod | grep blktap
blktap 124804 2 [permanent]
xenbus_be 8576 3 netbk,blkbk,blktap
> Greetings,
> Gernot Kieseritzky
>   
Bye,
Marcel

_______________________________________________
Xen-users mailing list
Xen-users@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-users