Ultrium

[Thedevastator]

Hi i have a novell 5.1 server with a cpq internal 32 bits fast ultra wide scsi bus .. i connected the ultrium to the port. gave me a performance of 6mb sec
now i seated an Adaptec 29160 Uw2 , and i get 7mb sec
this tape drive has all the latest drivers CDMS , ETC ETc
still only goes 7mb sec out of 15 mb native 30mb/sec compressed .. anyone know whats wrong?

 

[bjverzal]

I run an Ultrium drive in a UNIX environment. I am seeing over 13MB/sec.

What are your server specs ? Memory/CPU/disk type & size ?

What about file layout ? Look at 10 random files on the drive and look at their sizes. Do you have lots of little files ( < 1MB in size) ?

You will not see a higher throughput with small files because of file open/close overhead.

If you have fewer large files (> 1MB in size), you'll see higher throughput because the system is not so busy opening and closing small individual files. It is just streaming data from files already opened. If this sounds confusing, I'll explain more with word-picture diagrams...

Scenario #1:
10,000 files, average size = .5MB

# Begin Backup flow
Open file
copy data to tape
close file
read directory entry for next file
Return to Open file.

Scenario #2:
5,000 files, average size = 15MB

# Begin Backup flow
Open file
copy data to tape
close file
read directory entry for next file
Return to Open file.

In the first scenario, the system spends most of its' processing opening and closing files, but in the second scenariom it is just doing disk reads.

In my environment, I have about 100 files, each around 1.8GB in size. My system only opens and closes files 100 times. The majority of CPU cycles are spent on streaming data to the tape drive, which is where the higher throughput can be attained.

Feel free to write me directly at bjverzal@yahoo.com if you still have questions.

Bill.

 

[Thedevastator]

HI bill thanks for replying

well the system uses novell 5.1 and has the SP1
the cpu = intell Xeon 800mhz
disk = UW3 Raid 5 10 x 9.1GB CPQ 5300 controller(128mb cache)
SCSI = 32pci wide onboard
SCSI = Adaptec 29160UW2
MEM= 383 MB
(runs oracle server)
maybe the RAM on server is a bit low .. but it should be sufficient.
File backupping = done locally 50mb arc files 23 files x 50mb
should get me atleast 15mb/sec with this specs

on the 3585 external (VHDCI) LVD Ultrium
Any1 got any clues?

Thanks!

 

[bjverzal]

Is anything else on this 29160 SCSI bus ? Possible device contention ? My server does have 1GB of memory though.

What model is your server ?

Thanks, Bill.

 

[sjake1]

Backup is a processor and RAM intensive process.

RAM is cheap. Max out your RAM and you should see an improvement in througput.

Are you using any compression? Hardware compression should increase your throughput.

 

[UlteraTapeRAID]

Have you looked at the tape drive properties and set the tape block size to the largest size possible?

 

[deejay33]

Have you talked to IBM concerning this issue? The only reason I ask is that my company was interested in buying an ultrium from HP. Luckly before the purchase I spoke to a HP rep. who said that while the drive is supported under Novell NetWare 4.2 and up there are MAJOR preformance problems with 4.x and 5.x. They recomend you don't purchase the drive for use with these O.S.'s. It could be possible that the IBM may have similar preformance issues.
That may explain the very slow transfer rates.

Hope that helps,
DeeJay33

 

[deejay33]

I talked to HP again (I wanted to find out what the performance issues were) and they told me that Novell will have problems with all LTO technology dives. Whether it is made by IBM or HP will not matter. They said what the problem is, is the data stream is to fast for the Novell OS. The drive will continually have to reposition itself. This will not only cause the backup to go very slow but will greatly reduce the life of the drive. They also confermed that the problem was not fixed in NetWare 6.0. Their web site said 6.0 would work but the HP tech said they were going to change that soon. Sorry for the bad news.

DeeJay33

 

[dmen]

I've run into the same problem. I have an External Ultrium drive made by IBM on an IBM server. The server has 1GB RAM. After updating SCSI drivers, tape drive firmware, tape drivers, etc. the IBM tech support told me that I had too many small files (Word & Excel files). I have a total of 130GB worth of files. I start this backup at 9:00pm on Friday night. By the time the verify completes, its 2:00pm on Saturday afternoon. That is way too long. There's got to be a better way to speed things up.

Thanks,
DMen

 

[comtec17]

DMen,
You should start a new post instead of hijacking an old thread.

You will need to explain your setup a little better.

What type of adapter are you using to connect to your external drive?

What model server?

What CPU and speed?

What is the bus speed of your server?

Are you mirroring your internal disks?

What backup software?

Is anti-virus running?