[linux-lvm] SAN

[linux-lvm] SAN

[Jonathan Tripathy]

Hi Everyone,

I am considering my options at deploying a large SAN for our Xen cloud. 
We love LVM and find that it's great for expanding and shrinking LVs.

What is the best way to deploy LVM in such a way that multiple servers 
could access the LVs? Really what I'm looking for is a "common VG" for 
all of our servers. Note though that only one server will actually 
access each LV, however it would be cool if another server could make a 
snapshot to perform an rsync backup.

Any help or advice would be appreciated

Thanks

Re: [linux-lvm] SAN

[Stuart D. Gathman]

On Fri, 22 Apr 2011, Jonathan Tripathy wrote:

> What is the best way to deploy LVM in such a way that multiple servers could 
> access the LVs? Really what I'm looking for is a "common VG" for all of our 
> servers. Note though that only one server will actually access each LV, 
> however it would be cool if another server could make a snapshot to perform 
> an rsync backup.

This is what cluster LVM is for.  It provides a locking mechanism to
avoid conflicting changes to LVM metadata.

--
 	      Stuart D. Gathman <stuart@bmsi.com>
     Business Management Systems Inc.  Phone: 703 591-0911 Fax: 703 591-6154
"Confutatis maledictis, flammis acribus addictis" - background song for
a Microsoft sponsored "Where do you want to go from here?" commercial.

Re: [linux-lvm] SAN

[Jonathan Tripathy]

On 22/04/2011 17:38, Stuart D. Gathman wrote:
> On Fri, 22 Apr 2011, Jonathan Tripathy wrote:
>
>> What is the best way to deploy LVM in such a way that multiple 
>> servers could access the LVs? Really what I'm looking for is a 
>> "common VG" for all of our servers. Note though that only one server 
>> will actually access each LV, however it would be cool if another 
>> server could make a snapshot to perform an rsync backup.
>
> This is what cluster LVM is for.  It provides a locking mechanism to
> avoid conflicting changes to LVM metadata.
>
I'm a little confused on where CLVM fits into the "big picture". Let's 
say I have one SAN server, and 10 Xen Servers. Where do I install CLVM?

Re: [linux-lvm] SAN

[Jonathan Tripathy]

On 22/04/2011 17:42, Jonathan Tripathy wrote:
>
> On 22/04/2011 17:38, Stuart D. Gathman wrote:
>> On Fri, 22 Apr 2011, Jonathan Tripathy wrote:
>>
>>> What is the best way to deploy LVM in such a way that multiple 
>>> servers could access the LVs? Really what I'm looking for is a 
>>> "common VG" for all of our servers. Note though that only one server 
>>> will actually access each LV, however it would be cool if another 
>>> server could make a snapshot to perform an rsync backup.
>>
>> This is what cluster LVM is for.  It provides a locking mechanism to
>> avoid conflicting changes to LVM metadata.
>>
> I'm a little confused on where CLVM fits into the "big picture". Let's 
> say I have one SAN server, and 10 Xen Servers. Where do I install CLVM?
>
>
Am I correct in saying that I only need to install CLVM on my Xen nodes? 
Assuming that my SAN server is just a standard iSCSI server exporting a 
few targets. I would probably only have 1 LUN per vg (hense 1 PV per vg).

Is that correct?