Here’s my thoughts. If a
server is too big to back up over the LAN, then make it a LAN-free server. As
to how many server you should MAKE LAN-free and have share a single drive, I’d
say that depends. Let’s say that by moving a group of servers from
LAN-based to LAN-free, each server’s backup now takes only 2 hours
instead of 12. (totally feasible). Let’s also say that you
have a 12-hour backup window (also totally feasible). I’d say that
six server with a 2-hour backup window each can share a single tape drives. Now
let’s make it 20 tape drives with 120 servers, each with a backup
duration of 2 hours. I don’t see any problem with this
configuration. OK, I am pushing the 12-hour window and I didn’t
leave any room for error. So let’s make it 100 servers and 20 tape
drives, or 200 servers and 40 tape drives, each server with at 2-hour backup
window. I have no problem with this configuration.
Where the math of big numbers is really in
favor of such a config is when their full backup takes 6 hours, but the only
need to do that full backup once a month. Every other day of the month
they do an incremental that lasts only 15 mins. Let’s say we have 1
tape drive and 12 hours to use it. 21 systems can now share this tape
drive with time to spare. Each night, it will do a full backup one of
them, and the incremental backup of the rest. That’s 6 hours (for
the one full backup) and 5 hours for the other 20 incrementals (15 x 20 / 60),
and we’ve got time to spare. With that kind of math, 200 systems
can share 10 tape drives NO PROBLEM.
Should you do it? Why not. You’re
fully leveraging your infrastructure. Especially if by moving those
servers from LAN-based to LAN-free you’re now streaming the drives. They’ll
be happier and last longer.
From: Dominik
Pietrzykowski [mailto:dominik_pietrzykowski AT toll.com DOT au]
Sent: Tuesday, January 29, 2008
4:52 PM
To: Curtis
Preston; Veritas NetBackup; veritas-bu AT mailman.eng.auburn DOT edu
Subject: RE: [Veritas-bu] What's
Best Practice for SSO in NBU 5.1
Does not mean it’s
a good idea. You should only do it if you have to IMO.
From: Curtis Preston [mailto:cpreston AT glasshouse DOT com]
Sent: Wednesday, 30 January 2008
10:02 AM
To: Veritas NetBackup;
veritas-bu AT mailman.eng.auburn DOT edu
Subject: Re: [Veritas-bu] What's
Best Practice for SSO in NBU 5.1
I’ve seen hundreds.
From:
veritas-bu-bounces AT mailman.eng.auburn DOT edu [mailto:veritas-bu-bounces AT mailman.eng.auburn DOT edu]
On Behalf Of Veritas NetBackup
Sent: Tuesday, January 29, 2008
12:50 PM
To:
veritas-bu AT mailman.eng.auburn DOT edu
Subject: [Veritas-bu] What's Best
Practice for SSO in NBU 5.1
Anyone has good idea what's maximum Number of Media Server
we can share tape Drive using SSO.
I have seen SSO Drives Shared among 20 Media Servers, 35 and 45
Servers. I'm just curious to know.
