[linux-lvm] snapshots on shared fibre

[linux-lvm] snapshots on shared fibre

[Matt Schillinger]

I have a Xiotech Magnitude raid, that uses fibre ports to connect to
multiple servers. 

We do NOT use a SAN filesystem. What I am wondering is, can I use
snapshots that are mounted on 1 machine, where the original filesystem
is mounted on another machine. both machines are connected to the raid
via fibre.

My hope is that, since it is a second filesystem, and is readonly, this
operation will not cause problems..

Is this correct?


-- 
Matt Schillinger

mschilli@vss.fsi.com

Re: [linux-lvm] snapshots on shared fibre

[abbireddy venkatram reddy]

I think it will not work?..by the way which is file system your using..?
----- Original Message ----- 
From: "Matt Schillinger" <mschilli@vss.fsi.com>
To: <linux-lvm@sistina.com>
Sent: Saturday, March 29, 2003 12:27 AM
Subject: [linux-lvm] snapshots on shared fibre


> I have a Xiotech Magnitude raid, that uses fibre ports to connect to
> multiple servers. 
> 
> We do NOT use a SAN filesystem. What I am wondering is, can I use
> snapshots that are mounted on 1 machine, where the original filesystem
> is mounted on another machine. both machines are connected to the raid
> via fibre.
> 
> My hope is that, since it is a second filesystem, and is readonly, this
> operation will not cause problems..
> 
> Is this correct?
> 
> 
> -- 
> Matt Schillinger
> 
> mschilli@vss.fsi.com
> 
> 
> 
> 
> _______________________________________________
> linux-lvm mailing list
> linux-lvm@sistina.com
> http://lists.sistina.com/mailman/listinfo/linux-lvm
> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
> 

re: [linux-lvm] snapshots on shared fibre

[Greg Freemyer]

 >>  I have a Xiotech Magnitude raid, that uses fibre ports to connect to
 >>  multiple servers. 

 >>  We do NOT use a SAN filesystem. What I am wondering is, can I use
 >>  snapshots that are mounted on 1 machine, where the original filesystem
 >>  is mounted on another machine. both machines are connected to the raid
 >>  via fibre.

 >>  My hope is that, since it is a second filesystem, and is readonly, this
 >>  operation will not cause problems..

 >>  Is this correct?


 >>  -- 
 >>  Matt Schillinger

Matt,

I'm no expert on LVM, but I would be very surprised if the above works.

You need both machines to see a single consistent view of the COW table.

The COW table is possibly modified every time the r/w server writes to its LV.

You really need the snapshot to be implemented in the raid unit itself.

Or you could have the first server export the snapshot via nfs.

Greg
-- 
Greg Freemyer