ADSM-L

Re: Please help me NOT migrate

2004-04-20 13:21:05
Subject: Re: Please help me NOT migrate
From: "Stapleton, Mark" <mark.stapleton AT BERBEE DOT COM>
To: ADSM-L AT VM.MARIST DOT EDU
Date: Tue, 20 Apr 2004 12:20:34 -0500
From: ADSM: Dist Stor Manager on behalf of Eliza Lau
>Please help me NOT migrate the server to a different platform from AIX.

All right.
 
1. The only way to move TSM data from one operating system platform to another 
is by using the export/import functions.
 
2. Exporting 24TB of data, even running a direct export from the old TSM server 
to an import on the new server will take days. 
 
3. How to prove this? Perform a fairly simple test. Create a test TSM server 
on, say a Linux server. Attach enough disk to the Linux server to hold all data 
for one decent-sized (say, 20GB) TSM client. Run an export from the old server 
to the new server. Calculate the amount of data moved and the time it takes to 
perform the export. You're moving data from tape to disk; now figure (roughly) 
half again as much time will needed to move data from tape to tape.
 
There. You have a base line that you can show to the pointy-haired bosses and 
say, "It's going to take us a *long* time to move all of this data."
 
With a 3494, a viable alternative is to add a second TSM server and share the 
library. Start doing your new backups through the new server, and allow the 
data on the old server to slowly expire away. You will eventually *have* to do 
an export to move data (particularly archives), but if you allow six to nine 
months' worth of expiration on the old server, the export will be a lot less 
painful.
 
(This scenario's gonna go in the FAQ.)
 
--
Mark Stapleton