I hate to say it, because iSCSI is cool as hell and ‘just works’, but you’re better off just using NFS if you can get a license…  It ain’t cheap tho.  And FWIW, iSCSI could be faster than NFS, NFS is likely just as fast as iSCSI or faster in some cases.

 

Utilizing the lun create –b (as in your example below), re-mounting that newly exposed iSCSI LUN as a new device on LINUX then performing the backup is definitely the right idea.  This is the ‘norm’ for most NetApp iSCSI environments (Exchange, SQL, etc).

 

Glenn

 


From: owner-toasters@mathworks.com [mailto:owner-toasters@mathworks.com] On Behalf Of David L. Lambert
Sent: Wednesday, November 12, 2008 4:29 PM
To: toasters@mathworks.com
Subject: RE: Mounting read-only snapshots using open-iscsi?

 

I got mounting a snapshot to work.  I needed to do “iscsiadm … --rescan”, following this hint:

 

http://www.mail-archive.com/open-iscsi@googlegroups.com/msg01072.html

 

We have not implemented this with an actual NetApp yet, so I have no idea whether performance will be acceptable;  but thanks to all for the advice.

 

--

David Lee Lambert

Software Developer, Precision Motor Transport Group, LLC

517-349-3011 x223 (work) … 586-873-8813 (cell)


From: owner-toasters@mathworks.com [mailto:owner-toasters@mathworks.com] On Behalf Of David L. Lambert
Sent: Wednesday, November 12, 2008 11:22 AM
To: toasters@mathworks.com
Subject: RE: Mounting read-only snapshots using open-iscsi?

 

[…]

 

However, as I said, we don’t have an NFS license; we’ve also heard that NFS performance is poorer than iSCSI performance.  My guess is that some commands like the following ought to work:

 

Filer> lun map /vol/vol1/luns/lun11_snapforback linux-host 3

Linux> iscsiadm -m discovery --interface eth0 -t st -p 10.10.10.23 --login

Linux> iscsiadm -m node --interface eth0 -p 10.10.10.23 --login

Linux> mount /dev/sde /mnt/lun11-snap

 

When I do that, though, the set of available SCSI disk devices on the Linux host doesn’t change.  Perhaps this is an open-iscsi limitation instead?