TDP Oracle / 1.6TB+ DB / LANFree Backup taking 16 hours

[helmsdeep]

Hello all,

Good day to everybody...

We are backing up a single 1.6 TB oracle database via LAN free directly to a fiber attached TS3584 library with a LTO3 drive and LTO2 Tapes. It is taking almost 16 hours to backup!!

Parallely we are also running another 3 oracle DBs each of size 1.6 TB backups with separate drives and separate tapes on same server. So total its 4 DB backups going through 4 Drives to 4 Tapes at same time.

The scripts are written by DBA and we are just scheduling the scripts and monitoring whether backups are getting completed successfully or not through logs generated by backups.

Single Backup is taking 16 hours to complete, is this normal or am i doing anything wrong. How can i performance tune my oracle backups?

Please help.

Thanks and Regards,
Helmsdeep

 

[ChrisRees]

Hi

So you have 4 tape drives. How many fibre cards do you have on the TSM Server to run these drives on? If the answer is 1 you may have a bottleneck there.

Is the TSM server AIX? If so there are some parameters you can tune on the fibre cards, num_cmd_elems and max_xfer_size.

Are all 4 DB backups taking 16 hours or is it just 1 that is slow and the others are faster?

If its just 1 backup that is slow you need to look at the setup of that oracle server. It could be the disk subsystem of the oracle server cannot provide the data fast enough for the lan-free backup. Are all the oracle databases on similar disk hardware?

What O/S the oracle database servers?

CHeers

 

[helmsdeep]

Hi ilovetsm,

No, I have 6 Drives...and i dont know how many Fibre cards i have...can you tell how can i check on my server how many FCs i have?

Yes my TSM server is AIX 5.3 and TSM Server Version is 5.5.

All are taking more or less same time to complete. All are fired around same time at 9PM and finish by 2PM next day(15 hours or so).

Yes all oracle servers are of same OS and same configuration and they are running on AIX 5.3 OS and oracle version of 9i.

You did not answer one of my question which is...is this normal and in every environment does 1.6TB oracle DB take 15 hours to backup or is it only happening in my envi?

Thanks and Regards,
Helmsdeep

 

[Mikey D]

Oh wait reread your post, yeah at 30MB's LTO3 drives but with LTO2 tapes that's approx 15.5 hours per drive for 1.6TB.

Something I've never been positive on is if an LTO3 drive will write at LTO3 (80MB/s) or LTO2 (30MB/s) when using actual LTO2 media. Would be a good test to try to some actual LTO3 tapes.

 

[helmsdeep]

Yaaa...mee to thinking the same, to try out LTO3...but my client is not ready to buy it...so stuck with LTO2 tapes and LTO3 drives...cant help...

 

[GregE]

Something I've never been positive on is if an LTO3 drive will write at LTO3 (80MB/s) or LTO2 (30MB/s) when using actual LTO2 media. Would be a good test to try to some actual LTO3 tapes.

Based on physical specifications, I doubt LTO2 media will run at LTO3 speed in an LTO3 drive. The chip on the media is read by the drive. The drive determines that the media is LTO2 and acts accordingly. The LTO2 media has physical attributes such that it can only be written to at a maximum speed. (that's my theory anyway)

 

[hogmaster]

Hi Helmsdeep.
If I read you post correctly you start (or the DBAs crontab job) 4 different oracle backups at the same time from the same server?
I would advice you to ask the DBA to start the backups in a sequence, when the first backup is done the second should start. I would not be surprised if you
could at least half the time per DB this way. If this does not help ask the DBA to check if error checking is on during backup, turning this off could also help.
Error checking might only be active on one datafile so the DBA will have to check the whole datbase.

 

[GregE]

Also just a thought. Is your dsm.sys setting "COMPRESSION" set to YES. It should NOT be. Compression should happen at the tape drivet. If compressing at the client too, and running 4 DB backups at the same time, that's a ton of processing happening.

 

[ChrisRees]

Hi ilovetsm,

No, I have 6 Drives...and i dont know how many Fibre cards i have...can you tell how can i check on my server how many FCs i have?

Thanks and Regards,
Helmsdeep

At the AIX command line do the following two commands

lsdev -Cc adapter | grep fcs
lsdev -Cc tape | grep rmt

From this you should be able to see the number of fibre adapters and the number of tape drives assigned to each one. Post the output of these commands.