Help please - TSM DB full > 99%, but DB filespace has enough free space

[Sunhillow]

Hello altogether,
our TSM Server stopped operation with full database. But there is enough free space left on the DB LUNs!

Database Name: TSMDB1
Total Space of File System (MB): 403,173
Space Used on File System(MB): 305,301
Space Used by Database(MB): 283,792
Free Space Available (MB): 97,872
Total Pages: 14,596,416
Usable Pages: 14,593,312
Used Pages: 14,582,988
Free Pages: 10,324
Buffer Pool Hit Ratio: 98.0
Total Buffer Requests: 836,895,956
Sort Overflows: 0
Package Cache Hit Ratio: 99.6
Last Database Reorganization: 03/05/2019 11:56:29
Full Device Class Name: LTO6-PRIM
Number of Database Backup Streams: 1
Incrementals Since Last Full: 0
Last Complete Backup Date/Time: 03/05/2019 12:48:49
Compress Database Backups: No
Protect Master Encryption Key: No

How can I thee TSM to use the free space?
Server Version is 7.1.3.100, running on SLES11 SP4

 

[marclant]

What happens is that the server needs a minimum of free space to operate. When doing operations that are database intensive, like DB backups, expiration, online reorgs, etc., it needs a certain amount of temporary tablespace to move stuff around. 97 GB is really tiny.

At 400 GB, I'm assuming you only have 1 directory/LUN for the DB. If I were you, I'd add a 2nd DB directory LUN of 400 GB with the same type of disk. It's not that you necessarily need 400GB, but filesystems have to be the same size to be balanced. And we don't recommend going to more than 500 GB for a single DB filesystem, so it makes more sense to add a new directory/LUN. That will give you plenty of space to work with, room for growth, and better performance because the DB I/O will be split onto two filesystems.

More info:
https://www.ibm.com/support/knowled....srv.install.doc/c_srv_inst_db_mgr-linux.html

 

[marclant]

Also, what's the 22 GB of stuff on the database filesystem(s) that's not the database?

Total Space of File System (MB): 403,173
Space Used on File System(MB): 305,301
Space Used by Database(MB): 283,792

The space used on the filesystem is larger than the space used by the DB, the DB should use dedicated filesystems. If you move that 22 GB (305-283) on a different filesystem, that might be enough for now, until you can add more DB space.

 

[Sunhillow]

Thank you for the quick and competent answer!
The 22 GB are a miracle to me. Could this be the lots of 0-Byte-Files like .SQLCRT.FLG?

On the server in question we have 4 LUNs 100 GB each. What percentage of free space would you recommend? One additional LUN or two?

We have two other servers that seem to run into the same problem ... I always thought DB Space would be extended until disk space is completely in use

 

[marclant]

What percentage of free space would you recommend? One additional LUN or two?

I don't know the magic number, but I believe the server starts issuing messages about low space at 80% full. If you want to save the hassle of load balancing the DB, if you have the option to extend the 4 filesystems instead of adding new ones, that would be a better option. No harm in adding new filesystem, it's just the server will spend a while rebalancing the DB across all filesystems.

I always thought DB Space would be extended until disk space is completely in use

Well, with temporary tablespace, the space is used temporarily when needed by an operation, but it's released back when the operation is over.

 

[Sunhillow]

Hello marclant, on the link you posted above IBM recommends 50 GB extra space per 500 GB DB space. For sure this is a little bit too low.
We will extend all the LUNS to 150 GB tomorrow (today I have a leave day) which will hopefully be enough for a while.
Thank you very much indeed, there is still a lot to learn for me even after > 10 years of TSM

 

[marclant]

Thank you very much indeed, there is still a lot to learn for me even after > 10 years of TSM

I still learn after 17 years.

 

[moon-buddy]

I still learn after 17 years.

Doing TSM for 20+ years and still learning day-by-day

 

[subglo]

Doing TSM for 20+ years and still learning day-by-day

I'm doing TSM for 1+ years... and on Windows platform...

 

[Sunhillow]

I'm doing TSM for 1+ years... and on Windows platform...

Much luck to you!
An unplanned standstill once in a while will amplify the learning effect

 

[subglo]

Much luck to you!
An unplanned standstill once in a while will amplify the learning effect

Thanks, so far so good.
Had few of those small issues. Like for example when active log fills up full even though server was installed and configured according to IBM Spectrum protect Blueprint. And some issues on upgrading 8.1.5 to 8.1.7 etc. Worked everything out.