Have you come up with all your requirements yet? I think you need to stop 
looking at SANs or any piece of technology and first work with the business to 
document what they require. Once you've done this, present your requirements to 
vendors and see what they come back with.

To the consultant's point, you don't typically backup the SAN, you backup the 
data via the host owning the data. Various backup programs can do that 
streaming over the fiber channel backend straight to tape.

SANs, even replicated ones, don't negate the need for backups. If data gets 
corrupted or deleted or something, that corruption/deletion will get mirrored 
to the second device. Some vendors (e.g. NetApp) offer plugins that will 
actually make snapshot backups with the assistance of the host and store them 
on the same storage units. I'd suggest looking at this stuff.

Thanks,
Brian Desmond
[email protected]

c   - 312.731.3132

From: John Aldrich [mailto:[email protected]]
Sent: Tuesday, April 06, 2010 9:38 AM
To: NT System Admin Issues
Subject: RE: SAN question

Well, I think I have a pretty good handle on the meaning of the term SAN. 
Perhaps I should say "storage appliance." :) What I was originally looking at 
doing was having two "storage appliances" (i.e. NetApp, Equallogic, etc box) at 
physically separate sites, with one replicating to the other. To me, that makes 
a lot of sense, but then it does nothing for long-term data protection. I do 
not like the idea of "host-based" replication, as that adds yet another layer 
of complexity and another point of failure.

After discussing it with the D/R consultant, he suggested a single appliance 
and a tape backup, which of course, would require a PC or something to attach 
to the SAN and back it up to tape or run a backup service.

[John-Aldrich][Tile-Tools]

From: Mayo, Bill [mailto:[email protected]]
Sent: Tuesday, April 06, 2010 10:27 AM
To: NT System Admin Issues
Subject: RE: SAN question

I think the nomenclature makes things a little confusing.  We had that problem 
around here, too, for quite a while after setting up a SAN (many folks still 
have a problem).  I *think* you are using the term SAN to refer to a disk 
array.  A SAN is like a LAN, MAN, or WAN.  It is the network, not some 
particular thing that is attached to the network.  If you have 2 disk arrays 
that are connected, you do not have "2 SANs", you have 1 SAN and 2 disk arrays. 
 The SAN itself is comprised of the fibre channel switches and the things that 
connect to them (just like a LAN consists of switches/routers and the things 
that connect to them).  This concept is important, as it makes it clearer why 
you would attach a tape drive through the SAN.  By talking to your tape drive 
through the SAN, you remove the need for the tape drive to be in close physical 
proximity to your backup server.  If you are able to have geographically 
separated data centers connected to the same SAN, this means that you can have 
your tape backup automatically "off site".  The server doesn't know or care 
where the tape drive is, it just talks to it over the SAN.

We are doing something like this.  We have 2 data centers, and we have a disk 
array and a tape library in each.  The data is on the disk array is replicated 
in real time to the secondary data center.  Our backup system makes a copy of 
the backup to the secondary data center.  We are able to do this because we 
have plenty of fiber between these 2 locations, and both our LAN/MAN and our 
SAN make use of this fiber.

Bill Mayo

________________________________
From: Martin Blackstone [mailto:[email protected]]
Sent: Tuesday, April 06, 2010 10:14 AM
To: NT System Admin Issues
Subject: RE: SAN question
If you are just backing up to tape and your SAN goes down, where will you 
restore too? Do you have a spare disk pool to use?
If it was "me", I would be looking at a SAN solution that offers its own proven 
DR solution.
Since I only know NetApp, they have a tool called SnapMirror that is built into 
the OS. You pay for the license and plug in the serial.
Then setup your DR targets and let it rip. If your primary SAN goes down, you 
can do some clicks and bring the system online with all your data ready to 
access.

But you seem to be talking about a lot of things you want. You want DR, you 
want clustering. If you cluster, maybe you only need to backup to tape. Unless 
you want to buy a clustered SAN and a DR SAN. Of course if you are going to 
have a DR SAN, I assume you have a DR location?
I mean if the building burns to the ground do you have a location with the 
resources needed to keep the company running? Not just hold the data?

Have you narrowed this down to 3 vendors yet?

From: John Aldrich [mailto:[email protected]]
Sent: Tuesday, April 06, 2010 6:52 AM
To: NT System Admin Issues
Subject: SAN question

Guys, I'm still working on my storage needs, as the project I've been working 
on probably won't get approved until early next year at the earliest. I was 
talking to a D/R consultant recommended by one of the folks on this list. 
Unfortunately, he does not work with SMB clients, only large clients such as 
Coca Cola, etc.

I had been thinking of getting two SANs and having one replicate to the other 
for D/R purposes. Most of our operations run off the AS/400 so that would not 
be much affected (except if we are able to some how back up to the SAN, which 
is unlikely with our current AS/400, due to disk space limitations on the 400) 
one way or the other by the SAN project. The aforementioned consultant 
suggested that we look into getting just one SAN and a tape backup for it or 
online backup service instead of doing two SANs. Most of the data on the 
Windows side of things would be hard to replace if it died, so while it's not 
"critical" to our operations, it's still highly important.

What do you guys think of that suggestion? Would any of you guys do something 
like that? Why or why not?
Also, anyone know any D/R consultants in the North Georgia area who work with 
SMB clients?

[John-Aldrich][Tile-Tools]


















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