Ultrium 230 - Informix config?

[Marius Botha]

Hi,

I have just installed the much awaited Ultrium 230 on my N4000 cluster. Since the backups are a real pain and real slow, I need to tweak it a bit ... any ideas of how I can ammend these onconfig settings for Informix 7.31 ?

TAPEDEV /dev/level0backup
TAPEBLK 64
TAPESIZE 67108864 # DAT 3355400

I need maximum throughput, and can only think of changing TAPEBLK to 128, but what about TAPESIZE ... dont worry about TAPEDEV - that's a symbolic link to the new Ultrium driver.

I ran HP-UX 11.00, and have the latest patches installed for Ultrium.

Cheers

[Pete Randall]

TAPESIZE is just the max that the backup process will try to put on the tape - its' capacity. The only paramter that could possibly affect performance would have to be the blocking factor. Try it. I think you can probably go a lot higher than 128, though.

Pete

[Pete Randall]

And, if you really want performance, you should look at a backup package like OmniBackII or Legato Networker. They interface with the onbar facility and parallelize the output in order to keep the drive streaming. I doubt you're ever going to be able to take advantage of the speed of your Ultrium using ontape.

Pete

[Jose Mosquera]

Hi,

Pls take a look to these docs:

http://support5.itrc.hp.com/service/cki/docDisplay.do?docLocale=en_US&docId=200000062921693

http://support5.itrc.hp.com/service/cki/patchDocDisplay.do?patchId=PHCO_25424

Rgds.

[Marius Botha]

Thanks Pete,

But what should the TAPESIZE setting be for the Ultrium which can take 200GB?

thanks

[Pete Randall]

Marius,

I'm having a hard time finding the Informix doc I need to look at (Informix O D S Backup and Archive Guide), so I ran it by my DBA. He "thinks it's 2^32-1 Kb or over 4096 Gb." He's "pretty sure its an unsigned long int expressing tape size in KB." And, he also picked up on TAPEBLK, "too small and too many gaps on the tape." Crank that block size way up and run some comparisons.

I really doubt that you're going to be able to do that Ultrium drive justice with ontape - sorry to repeat myself but I just can't see it happening with a facility that was designed with DAT tapes in mind.

Pete

[Steve Lewis]

Use TAPESIZE 209715200 for 200Gb native

We get 400Gb onto an Ultrium 1, the compression is so good, because we use 64 bit informix / HP-UX. So you might be able to bump the TAPESIZE up to 800Mb even for an Ultrium 2.
I recommend you set it very high and see how much you actually get onto a tape.

Ensure that you have the correct minor number for the tape device file, to enable hardware compression. The auto-installer doesn't always use the correct one when creating device files.

Here are mine.
crw-rw-rw- 2 bin bin 205 0x071000 Nov 30 2001 6m
crw-rw-rw- 2 bin bin 205 0x071080 Nov 30 2001 6mb
crw-rw-rw- 2 bin bin 205 0x071040 Nov 30 2001 6mn
crw-rw-rw- 2 bin bin 205 0x0710c0 Nov 30 2001 6mnb

Set the TAPEBLK to at least 128 and preferrably 256 for a device that fast.

> 3 points please ;-) (nearing my 2nd hat)

[Vincent Farrugia]

Hello,

For an Ultrium tape drive, the block size recommendation is 32K. There is no point in increasing it further.

See below for details:

http://www.hp.com/products1/storage/products/tapebackup/ultrium_tapedrives/ultrium230/infolibrary/whitepapers/ultperfpress.pdf

HTH,
Vince