Re: [Iscsitarget-devel] Problem with IET and XenSource

[Ross S. W. W. <rw...@me...>]

I have found for my environment that fileio works best for VMs and file =
servers while blockio works best for databases.

Now if you are doing raw block io to the VMs, raw partitions, then =
blockio may work better, but if the VMs exist in virtual disk files then =
fileio may be best.

I'd benchmark them and see. It may turn out that vmware works best with =
fileio and xen with blockio.

-Ross


-----Original Message-----
From: S. J. van Harmelen <sv...@dd...>
To: Ross S. W. Walker
CC: iscsitarget-devel <isc...@li...>
Sent: Wed Nov 14 18:03:01 2007
Subject: RE: [Iscsitarget-devel] Problem with IET and XenSource

Thanks very much Ross, your help is greatly appreciated!

I will try this config tomorrow in the maintenance window.

One last thing (while I'm asking :).. blockio is the right option for
vmware and xensource disks, right? Vmware uses .vmdk files as disks and
xensource uses lvm volumes.

Sander



On Wed, 2007-11-14 at 17:57 -0500, Ross S. W. Walker wrote:
> S. J. van Harmelen wrote:
> >=20
> > Damn... I read something about that earlier, but didn't think of =
that
> > now! I guess you have a point, I do use multi-pathing for the=20
> > connecting
> > to our storage. Will give this a go to test it.
> >=20
> > Can you tell me what to add to my target description to set=20
> > the SCSI-ID?
> >
> > At this time my ietd.conf looks like this:
> >=20
>=20
> Try this config out:
>=20
> Target iqn.2007-08:storage.172.16.0.100
>           Lun 0 =
Path=3D/dev/mapper/vmware,Type=3Dblockio,ScsiId=3D0001000100010000
>           MaxConnections          1
>           InitialR2T              No
>           ImmediateData           Yes
>           MaxRecvDataSegmentLength 8192
>           MaxXmitDataSegmentLength 8192
>           MaxBurstLength          262144
>           FirstBurstLength        65536
>           MaxOutstandingR2T       8
>           HeaderDigest            None
>           DataDigest              None
>           Wthreads                8
>           QueuedCommands          64
>=20
> Target iqn.2007-11:xen.storage.172.16.0.100
>           Lun 0 =
Path=3D/dev/mapper/xen,Type=3Dblockio,ScsiId=3D0001000100020000
>           MaxConnections          1
>           InitialR2T              No
>           ImmediateData           Yes
>           MaxRecvDataSegmentLength 8192
>           MaxXmitDataSegmentLength 8192
>           MaxBurstLength          262144
>           FirstBurstLength        65536
>           MaxOutstandingR2T       8
>           HeaderDigest            None
>           DataDigest              None
>           Wthreads                8
>           QueuedCommands          64
>=20
> >=20
> > Does this look ok (besides the fact that I mis the
> > SCSI-ID)?                                            =20
>=20
> The options I deleted from your config are "static" and can't
> be changed from their defaults.
>=20
> MaxConnections should always be 1, as the software currently
> only supports 1 connection per session.
>=20
> I set the optimal values for the others.
>=20
> I would think of better iqn names though and avoid ip addresses.
>=20
> Say:
>=20
> Target iqn.2007-08.com.example:storage.disk.vmware.guests1
>=20
> Target iqn.2007-08.com.example:storage.disk.xen.guests1
>=20
> <snip old conversation>
>=20
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>=20

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