TSM Database ???

[cwilloug]

I have a TSM db question for you,,, wondering if my logic is correct or flawed.

Currently we have 290 nodes on TSM, management would like (potentially) to add 220 additional nodes.

Currently:

Available Assigned Maximum Maximum Page Total Used Pct Max.
Space Capacity Extension Reduction Size Usable Pages Util Pct
(MB) (MB) (MB) (MB) (bytes) Pages Util
--------- -------- --------- --------- ------- --------- --------- ----- -----
184,320 145,728 38,592 35,536 4,096 37,306,368 27,878,468 74.7 75.6


Now, if I have a max reduction of 35,000 and max extension of 38,000 (lets call them the same #). So if we are at 75% and use the max reduction, we would be at 100% db Util, then the reverse would be true, 75% DB Util then extend to the max, would put me at 50% db Util. I do also know that it depends on what kind of data the new nodes are backing up, but would this be a good "guesstamate"?

Usually how many nodes do you put on one TSM instance?

 

[rore]

Hi,
Yes about the 100%. But the reverse will give you 60% util, not 50%.

It doesn't depend on the type of data. It doesn't depend on the number of nodes (well, let's say indirectly yes).

It depends on the number of objects that you will track, that depends on the frequency of the backups, the ratio change on your clients, the number of files on your clients, and the retention policies.

1 object is approx 800 bytes in TSM database, 1 copy object (copy storage pool) is 200 bytes. (metadata)

Hope this helps,

Rudy

 

[heada]

Archive objects are larger than backup objects so if you do more archives, you'll see a larger database growth.

-Aaron

 

[rore]

Archive objects are larger than backup objects so if you do more archives, you'll see a larger database growth.

-Aaron

Actually archive and backup objects have the same estimated size.

Correction to my first post:

Each stored version of a file requires about 400 to 600 bytes of database space.
Each cached file, copy storage pool file, and active-data pool file requires about 100 to 200 bytes of database space.
Overhead could require up to 25% in additional space.

*From Administrator's Guide v5.5 http://publib.boulder.ibm.com/infoc...pic/com.ibm.itsml.doc/anrlgd55575.htm#plndbsp

Rudy

 

[cjhood]

cwilloug,

Just to chip in with my 2c...

Usually how many nodes do you put on one TSM instance?

This really depends on your environment. I'm running around 300 nodes off one instance and the server is starting to struggle a wee bit (simply because it wasn't specced for that many initially). If you're running a TSM server with a high level of throughput, theres nothing to stop you adding more clients. I've heard whispers that IBM recommend 100ish nodes per server, however I haven't ever been able to officially confirm this...

The big factor is the database (as you've identified), and your retention. I would personally consider defining those new clients on a brand new TSM instance (to try and cater for growth over the long term). IBM recommend a TSM DB somewhere in the range of 100-120Gb max for performance and recoverability. Yours is already over this, and will only head north from here.

V6.1 will solve all these problems and more, of course.

-Chris

 

[cwilloug]

Yes, I am aware of TSM 6.1 using DB2, and its solutions to the DB limits, but we are not there yet...

Thanks for everyone's input, you confirmed what I was thinking.

CJHOOD - of thoses 300 nodes you are running, how many are in the same room or building as your TSM server? My current 290 nodes are in the same room/building. The additional 220 nodes would be from across the state.

 

[cjhood]

cwilloug,

The vast majority of them are in the same location, I'd say no more than half a dozen running over slow links (or otherwise off-site).

I've got the advantage of having some smaller TSM instances at other sites to reduce the network load. From what you're saying I'd guess that those 220 are scattered around rather than being in a few main locations?

-Chris

 

[cwilloug]

Yes, the new additions are scattered in 9 different locations throughout the state. I did just add two linked ethernet cards to my system for this reason.

 

[cjhood]

I wouldn't say that backing up nodes at other sites would change the situation much - as long as your network links are big enough. It'll all come down to the power of your TSM server and how well it copes with a potential doubling of workload. And of course the size of the DB, and how much it grows over time.

-Chris