Veritas-bu

[Veritas-bu] Dual port HBA - 1 port disk, 1 port tape...good or bad?

2005-07-27 14:28:18
Subject: [Veritas-bu] Dual port HBA - 1 port disk, 1 port tape...good or bad?
From: ewilts AT ewilts DOT org (Ed Wilts)
Date: Wed, 27 Jul 2005 13:28:18 -0500
On Wed, Jul 27, 2005 at 11:09:19AM -0400, Jack L. Forester, Jr. wrote:
> Now, to get to my point, I'm aware that it's usually considered bad form 
> to put tape and disk on the same port of an HBA.  What about tape and 
> disk on different ports of the same HBA?  I would guess that if the card 
> has sufficient bandwidth and the ports are truly independent of each 
> other (not sharing any settings) that this configuration would be OK.

Generally speaking, you should not mix tape and disk but that doesn't
mean it won't work or give you adequate performance.  We mix disk and
tape on the same HBA here (we used to be separated but eventually
collpased the SANs).  

One of thoughts is that not only is mixing disk and tape on the same HBA
is suboptimal, but ideally you should use cards from different vendors.
That allows you the flexibility to have separate configuration files and
to unload the driver if you need to.

There's ideal, and then there's reality...

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