[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Xen-users] High Number of VMs

Viele GrÃÃe.

Am 21.09.2011 um 11:14 schrieb Bart Coninckx <bart.coninckx@xxxxxxxxxx>:

> On 09/14/11 10:11, Christian Motschke wrote:
>> Am 13.09.2011 um 17:31 schrieb John Madden:
>>>> Any advantage on using large luns+LVM instead of independent LUNs
>>>> appart from snapshots? (according to Novell support LVM on top of LVM
>>>> is a bad thing...). I remember reading that Xen itself implements some
>>>> kind of locking...
>>> I think easier management is the key.  If you're already managing the SAN 
>>> and assigning LUNs to your boxen, then managing multipath.conf across your 
>>> cluster, it's nice to only do that 4 times for a couple TB rather than once 
>>> for each VM, for example.
>> I just want to add, what the iscsi-SCST guys suggest (from 
>> http://scst.svn.sourceforge.net/viewvc/scst/trunk/iscsi-scst/README?revision=3852&view=markup)
>> 4. If you are going to use your target in an VM environment, for
>> instance as a shared storage with VMware, make sure all your VMs
>> connected to the target via *separate* sessions, i.e. each VM has own
>> connection to the target, not all VMs connected using a single
>> connection. You can check it using SCST proc or sysfs interface. If you
>> miss it, you can greatly loose performance of parallel access to your
>> target from different VMs. This isn't related to the case if your VMs
>> are using the same shared storage, like with VMFS, for instance. In this
>> case all your VM hosts will be connected to the target via separate
>> sessions, which is enough.
> Hi,
> would this translate into using a seperate iSCSI target for each VM versus a 
> seperate iSCSI LUN?
Yes, I think this is meant. But I have not tried it this way.
> thx,
> B.

Xen-users mailing list



Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.