Veritas-bu

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

2005-07-27 15:06:43
Subject: [Veritas-bu] Dual port HBA - 1 port disk, 1 port tape...good or bad?
From: pkeating AT bank-banque-canada DOT ca (Paul Keating)
Date: Wed, 27 Jul 2005 15:06:43 -0400
What's a good way around this???
Cheap appliance type Media servers? Like V210s with a couple of HBAs to
interface to banks of tape drives.
4x LTO2 or 2x LTO3 or something per V210 with a dual port 2gb HBA

I currently have 8 LTO2 drives on two 2gb HBAs, in a v880 with dual gigE
cards.

However, I know my bottleneck is the 2gb DWDM link between my sites (4
tapes in a library on each side of the DWDM link)

Writing two tape at a time, using ITC.

Paul

> -----Original Message-----
> From: veritas-bu-admin AT mailman.eng.auburn DOT edu 
> [mailto:veritas-bu-admin AT mailman.eng.auburn DOT edu] On Behalf Of 
> Charles Ballowe
> Sent: July 27, 2005 2:46 PM
> To: Veritas List
> Subject: Re: [Veritas-bu] Dual port HBA - 1 port disk, 1 port 
> tape...good or bad?
> 
> 
> keep in mind that the bandwidth limits on a 32 bit, 33Mhz PCI bus are
> 132 MB/sec. That's the biggest limit I run into in my backup
> environment, and someone else mentioned it. That's the agregate for
> all devices on the bus. If you have a network card and modern tape
> technology, you can pretty much max out that bus bandwidth with just
> the network reads and tape writes. On one of my media servers, I'm
> quite happy if I get 40MB/sec in from the network and write (inline
> tape copy) that out to 2 tape drives. That's pushing the bus at
> 120MB/sec.
> 
> -Charlie
> 
> On 7/27/05, Jack L. Forester, Jr. <jack.l.forester AT lmco DOT com> wrote:
> > I may be getting some new HBAs to put into my master servers.  They
> > would be dual port cards.  Presently, my tape devices are 
> on an older
> > JNI HBA which requires me to reboot the server (Sun E450) to add
> > devices.  As an additional bonus, the new HBAs would be 2Gb 
> with the old
> > ones 1Gb.  I'm considering moving the tapes to the new HBA. 
>  However,
> > the main reason we are going to get the HBAs is to attach to our
> > enterprise SAN for disk storage.
> > 
> > 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.
> > 
> > Any thoughts?
> > 
> > --
> > Jack L. Forester, Jr.
> > UNIX Systems Administrator, Stf
> > Lockheed Martin Information Technology
> > (304) 625-3946
> > 
> > _______________________________________________
> > Veritas-bu maillist  -  Veritas-bu AT mailman.eng.auburn DOT edu
> > http://mailman.eng.auburn.edu/mailman/listinfo/veritas-bu
> >
> 
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