Ultrium 230 drive backup is sloooooow

[Paul Bold]

We installed an Ultrium 230e drive for capacity (we back up around 50GB per night).

Expected backup speed to be faster than previous OnStream drive (around 70MB/min) but is about the same.

Info is...
Ultrium drive is attached to its own Adaptec 29160N card.
OS is NT 4 SP5 and its IRQ is fine (not in conflict)
Server is Intel based PIII 750 with 512MB ECC RAM
Drives are E: RAID 5 (consists of 5 7200 rpm drives (one spare))
and F: Single EIDE 7200 rpm 40GB
Using ArcServe v6.61 SP2 and using software compression with hardware compression truned off.

Downloaded PAT and get the following results with the quick estimate...
Drive E: 6.77MB/s (406.2 MB/min)
Drive F: 3.85MB/s (231MB/min)

Any clues as to how I can get this drive up to a reasonable speed - the backup is taking 12 hours!

Its a busy server with mainly lots of 'small' files - only big databse is Exchange on Drive F which I don't back up anyway.

Lots of experts in here - you can hopefully help me!

Paul

[Leif Halvarsson_2]

Hi

At first I would recommend you turning off software compression and use hardware compression instead. Software compression will increase cpu load much and the Ultrium hardware compression is very fast.

Large number of small files will put high stress of the disk/filesystem. Check the cpu/disk load when backup is running (software compression off). If cpu low,disk high you need better disk/filesystem performance, perhaps using RAID 1+0 can help or you need to buy faster drives.

[Graham Rawolle]

We had a similar problem which we resolved by installing the latest Adaptec SCSI drivers and latest LTO firmware - both are important. Also use hardware compression, I agree with other respondent in that software compression may slow things down a lot. We are using NT 4 SP6 and Backup Exec with HW RAID 5 10,000rpm drives and get about 260MB/min.

[Paul Bold]

Guys

thanks for the help - have got the most up to date Firmware and drivers for NT - turned off software compression and enabled hardware compression - results as follows...

E: (RAID5) - 40,284 MB backed up (117,928 files) throughput 102MB/min
F: (single 7200rpm) - 11,480MB backed up (32,748 files) throughput 108MB/min
Catalog file - 261MB throughput 825MB/min !!!

two possible software interferences are Diskeeper (now turned off) and Netshield Anti Virus - Does the virus scanner check files as they are being backed up?

Will post results up in a couple of days - but in the meantime any other idea most welcome

[Leif Halvarsson_2 · Accepted solution]

Hi

I dont think your main problem is tape drive performance but disk/filesystem performance. One clear indication is thst you get much better throughput with the 261MB file then with your "ordinary" data.
This is a very common problem with high performance tape devices (such as Ulrtium). The tape device is faster then the disk/filesystem. The "standard" solution is to run several disk agents in paralell, I dont know if ArchServe support this. However, as you back up only two volumes, this can at best double your throughput.

Other ways to get performance:

- Using more disks/filesystems (if ArchServe support paralell disk agents).

- Using faster disk drives. A 7200rpm EIDE drive have a seek time of perhaps 10ms, a 15000rpm SCSI drive about 3.5 ms. A such drive can locate and read the data about 3 times faster compared to the EIDE drive.

There is a whitepaper about Ultrium and backup performance, you can find it at:
http://www.hp.com/products1/storage/products/tapebackup/ultrium_tapedrives/ultrium230/infolibrary/whitepapers/ultperfpress.pdf

[Paul Bold]

Thanks Leif - looks like another set of disks then...

Pity that HP doesn't warn you about this problem when you buy Ultrium drives - they only advertise the drive's speed and don't give any indication of its relevance to the disk / file system performance

By the way, the link doesn't work - anywhere else to download it?

[Leif Halvarsson_2]

Hi
I send the file attached instead.

[Drs. Bov]

If you go to Adaptec finder:
http://www.adaptec.com/worldwide/product/productfinder.html you will see that 29160 N is not advised for external LVD drives because it has an external 50 pins connector for Ultra SCSI devices. You can of course try a brea-out cable from the internal 68 pin slot or use 29160LP.