Xen 3 and Core-iSCSI

[tuhl]

Hi all,

after some frustrating experiments using open-iscsi with FC5 and Xen. I
would like to do the same tests with Core-iSCSI. I saw some success
messages with FC5 already. Is there anybody using
it together with Xen?

Yours
Tom

[is...@digitaltadpole.com]

I haven't played with Xen yet, but will very soon (this week or next).
I'd be interested in comparing notes on this topic. It appears that
the latest release available (1.6.2.6) is the ticket for Core-iSCSI and
FC5 and the later kernels.

It also appears (to someone like me who hasn't looked very closely)
that Open-iSCSI is trying to make use of the latest kernel structures
and the ground keeps changing underneath them. They will eventually
have a really good solution, but for now it looks like a lot of careful
selections of the best rev of Open-iSCSI matched with the best rev of
the kernel plus intensive reading of mailing lists for patches is
needed for stability. (this is all an almost uneducated guess).

I would note that when you are playing in this area (that is, pretty
close to the bleeding edge) you'd better not expect "instant
gratification" from any of the solutions you pick. It's pretty easy
to go "off the page" into uncharted/untested territory.

Best wishes, good luck, and keep me posted (and I'll do the same)...

Mike Mazarick

[is...@digitaltadpole.com]

I swiped this posting off of the Xen discussion list.. it seemed
useful... (you've seen it but others haven't)

http://lists.xensource.com/archives/html/xen-users/2006-05/msg00666.html

=========================================
Re: [Xen-users] iSCSI-LUN as VBD
from [Peter Simon] [Permanent Link][Original]

To: Martin Heller <martin.heller@xxxxxxxxxxxxxxxxx>
Subject: Re: [Xen-users] iSCSI-LUN as VBD
From: Peter Simon <Peter.Simon@xxxxxxxxxxxxxxx>
Date: Tue, 23 May 2006 18:32:02 +0200

Martin Heller wrote:
> Peter Simon wrote:
> > at the list I read the that some guys have this setup working:
> > Access though iSCSI in dom0 to the target, starting domU directly form
> > iSCSI-LUN as vbd.
>
> We got xen-2.0.7 with Debian Sarge 2.6.11 and core-iscsi 1.6.2.5 as
> initator and iscsi-tools 3.3.
>
Thanks for this hint.
I've tested core-iscsi and it works pretty well with xen-3.0.2, SLES9,
Kernel 2.6.16 and our NetApp-Box :-)

Now I'm asking me, if their is something in core-iscsi to do persistent
LUN mapping, like this /dev/disk/by-id/...-thing in open-iscsi?

Schöne Grüße aus München ;-)

Peter

--
Leibniz Computing Centre Peter Simon
High Performance Systems http://www.lrz.de
Boltzmannstrasse 1 phone: +49 89 35831 8723
D-85748 Garching/Munich fax: +49 89 35831 9700

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[tuhl]

Here my testsetup:

Server: 2.6.16-1.2289_FC6xen with iscsitarget-0.4.13
Client: FC5 (2.6.16-1.2133_FC5) and core-iscsi-v1.6.2.6

initiator:
CHANNEL="0 1 eth1 192.168.1.100 3260 0"

iscsi_device_maps:
DEVICE="0 0 1 disk0"

When I mount channel 0 and start bonnie++ the client hangs.

[tuhl]

On the console I get:

BUG: soft lockup detected on CPU#0!

EIP is at scsi_request_fn+0x32e/0x366 [scsi_mod]

Perhaps this is a bug in the scsi_module, which was also the problem I
had with open-iscsi.

Yours
Tom

[Ming Zhang]

suggest u to run it with a vanilla kernel like 2.6.17 and see if can
reproduce. if not, then you need to fill a bug report to FC,