cancel
Showing results for 
Search instead for 
Did you mean: 

Tru64 and IBM LTO-4

hkyeakley
Advisor

Tru64 and IBM LTO-4

Hello,

I have a Spectra Logic library with 12 LTO-4 drives. I can write to the drives at around 100 MB/s from a Linux host, but I get very poor performance from a Tru64 host. I'm wondering if it's because I haven't placed an IBM LTO4 stanza in my /etc/ddr.dbase file and recompiled the hardware database.

Is anyone else out there running LTO-4 with Tru64? If so, did you have to do anything to get them to work?

I've got a call in to Spectra Logic, asking them to contact IBM and get the exact text I need to add the driver. I just thought I'd blast a question out here in case someone already had a working setup.

Thanks.
6 REPLIES
Martin Moore
HPE Pro

Re: Tru64 and IBM LTO-4

You do need to add an entry to ddr.dbase. I don't have the exact text you need, but perhaps someone else will post it.

In addition, if you're running V5.1B-4 (aka V5.1B + patch kit 6), then you would be well advised to install the following ERP: http://h30097.www3.hp.com/unix/erp/c01627023.html . This corrects a problem with tape devices that support ALUA, of which the LTO-4 is one.

Martin
I work for HP
A quick resolution to technical issues for your HP Enterprise products is just a click away HP Support Center Knowledge-base
See Self Help Post for more details

hkyeakley
Advisor

Re: Tru64 and IBM LTO-4

OK, to give a little more information.

I have this SL library at my main site. I have a smaller library which also contains IBM LTO4 drives in it at my DR site.

Every week I take a tape backup of my production database here. I'm using Symantec NetBackup and the speeds I get on my LTO drives here is terrible: 10 MB/s to 20 MB/s.

I take the tapes and mail them to my DR site and load them in the library there and restore the files to an ES80 at my DR site. The restore typically screams. I get restore speeds anywhere from 50 MB/s - 100 MB/s.

I've looked at all kinds of things at my ES80:
- patch kit level
- settings of cam kernel parameters
- HBA model
- HBA firmware level
- SAN switch firmware level
- etc...

I can't figure out what is making my LTO4 drives rock at my DR site while the 20 Tru64 boxes I have at my main site do good to hit 10 MB/s to 20 MB/s.

Does anyone have a suggestion on things I could check?

Thank you.
Rob Leadbeater
Honored Contributor

Re: Tru64 and IBM LTO-4

Hi,

What's the exact configuration at your primary site ? Are the machines all as powerful as the ES80 at the DR site ?

You mention 20 Tru64 boxes, are they all writing to the library via fibre or via LAN ?

Cheers,

Rob
hkyeakley
Advisor

Re: Tru64 and IBM LTO-4

Of the 20 something Tru64 systems I have, 3 of them have the special SAN Media server license installed that allows them to backup directly over the SAN. The remaining 17ish system back up over the LAN. I understand the LAN based systems are going to take a while to backup, but the performance I'm getting out of the Tru64 boxes is terrible.

Furthermore, my master and media servers are all Linux, and they can write to my library at LTO-4 speeds. Whatever I'm experiencing seems to be isolated specifically to my Tru64 boxes.

With that said:

I'll attach a script with output of the following:

hwmgr v hier | head (to show the platform)
psrinfo | wc -l (to show the # of procs)
psrinfo -v (for verbose info)
vmstat -P (for memory)
hwmgr -show fibre -adapter (for HBA info)
dupatch -track -type kit (for patch info)

I've asked my SAN guys to triple check the zoning. For the time being, I'm taking their word that everything is zoned correctly.

Both my production box here and my DR system have only 1 stanza in the /etc/ddr.dbase file that refer to an Ultrium drive. (Keep in mind I have IBM drives.)

< --- excerpt from /etc/ddr.dbase -->
2341 # Matches "Ultrium"
2342 #
2343 Type = tape
2344 Name = "HP" "Ultrium"
2345 #
2346 #
2347 PARAMETERS:
2348 TypeSubClass = lto # Linear Tape Open
2349 TagQueueDepth = 0
2350 MaxTransferSize = 0x0ffffff # (16MB - 1)
2351 ReadyTimeSeconds = 120 # seconds
2352
2353 #
2354 # Ultrium mode select parameters for rewind after reset behavior
2355 #
2356 MODESELECT:
2357 ModeSelectNumber = 0
2358 SavePage = No
2359 PageFormat = scsi2
2360 BlockDescriptor = yes
2361 TransferLength = 16
2362 Hdr.Tape.BufferMode = 0x1
2363 Data.UBYTE[0] = 0x3D #Vendor Unique Page Code 0x3D
2364 Data.UBYTE[1] = 0x02
2365 Data.UBYTE[2] = 0x01
2366 Data.UBYTE[3] = 0x00
2367
2368 #
2369 # Ultrium density parameters
2370 #
2371 DENSITY:
2372 #
2373 DensityNumber = 0,2,4,6
2374 DensityCode = default
2375 CompressionCode = 0x0
2376 Buffered = 0x1
2377
2378 DENSITY:
2379 #
2380 DensityNumber = 1,3,5,7
2381 DensityCode = default
2382 CompressionCode = 0x1
2383 Buffered = 0x1

<-- excerpt -->

If there's any other information you need, please feel free to ask. I'm completely stumped on this one.
Rob Leadbeater
Honored Contributor

Re: Tru64 and IBM LTO-4

Hi,

OK - a 32 CPU GS1280 should have enough grunt !

The one obvious difference between the Prod and DR boxes, is that Prod appears to be part of a cluster.

Check that the file systems that you're backing up are local to the node that's running the backup, otherwise all of the data will be going over the cluster interconnect.

# cfsmgr

Hope this helps,

Regards,

Rob
hkyeakley
Advisor

Re: Tru64 and IBM LTO-4

Yes, the GS1280 is part of a cluster. However, the 2nd node was deactivated a few years ago, and so now this system is a 1 node cluster where the interconnect has been terminated. I realize this completely defeats the purpose of having a cluster, but it was one of those "business decisions" that we admins are told to implement every now and then.

Any other thoughts?