On Mon, Nov 28, 2005 at 10:11:34PM -0600, Williams, Kristopher L wrote:
>  
> For one of my customers, we have a dedicated disk SAN with a separate
> Tape fabric for backups. We backup most servers over the network, unless
> it's large (~200gb) at which point we put another HBA in for tape
> connection. With the blades we are using, we only have 2 HBA ports to
> use for each blade. Both are going to the disk SAN for redundancy. This
> leaves me with pulling quite a bit of data over the LAN for backups.
> 
> Anyone have any creative ideas? I really don't want to mix tape and disk
> on the same SAN (I know this has been debated here before). I know I can
> just put into effect a policy that says "no more than ~200gb per blade",
> but it feels like there should be a better answer. 

We mix disk and tape on the same SAN (the media servers all have
SAN-based DSSUs) but the vast majority of our backups go over a
dedicated GigE backup network.  So far it's working.  Whether it's
optimal or not I don't really know, but it does work.  We put about 35TB
per week to tape (8 SDLT 220 transports).

We have an informal policy that says that large hosts must have a GigE
backup connection and smaller hosts are fine at 100mbps connections.
Slower backups mostly get staged to disk first.

        .../Ed

-- 
Ed Wilts, Mounds View, MN, USA
mailto:ewilts AT ewilts DOT org