topic Linux backup across SAN in Operating System - Linux

Linux backup across SAN

Brent DeGennaro — Mon, 21 Feb 2005 08:22:52 GMT

We're attempting to backup our Linux boxes across the SAN but have had no luck so far. Does anyone know what drivers we need to have installed? Here's a little info about our set up.

Data Protector 5.1

ESL9322 Library

e1200 Network Storage Router

Red Hat Linux Advanced Server release 2.1AS

Emulex LightPulse LPFC Driver Version: 4.20q
HBA: Emulex LightPulse LP950 1 Gigabit PCI Fibre Channel Adapter

$ /sbin/lsmod
Module Size Used by Not tainted
st 31536 0
sg 36644 0 (autoclean)
deadman 3036 3
bcm5700 105644 2
bonding 56628 2
md 66336 0 (unused)
lvm-mod 64576 18
lpfcdd 267752 4
cciss 45536 5
sd_mod 13372 6
scsi_mod 123636 4 [st sg lpfcdd cciss sd_mod]

I can start the backup session and a tape is loaded into the drive but nothing is ever written to the tape. Any help would be greatly appreciated.

Thanks

Re: Linux backup across SAN

Peter Godron — Mon, 21 Feb 2005 08:31:52 GMT

Hi,
what error messages have you found so far?

Re: Linux backup across SAN

Brent DeGennaro — Mon, 21 Feb 2005 09:02:41 GMT

I never actually receive an error message. The tape is pulled from the appropriate media pool(only one tape in the pool) and loaded into the drive. After a short wait(5 minutes or so) a mount request is issued for another tape with nothing ever being written to the first tape.

Thanks

Re: Linux backup across SAN

Steven E. Protter — Mon, 21 Feb 2005 18:14:40 GMT

I am a bit confused.

What software are you using to back up across the SAN?

Is the zoning set up appropriate on the SAN to allow the backup device/software combination to do the job?

You might want to look at the logs of the san to see whats going on here.

SEP

Re: Linux backup across SAN

Glenn N Wuenstel — Tue, 22 Feb 2005 08:10:38 GMT

Brent,
I've done this myself. Check out the Enterprise Backup Solutions (EBS) web page at: www.hp.com/go/ebs
There is an EBS123 section.
But I'd say that what you are seeing is that you have a device ID mismatch. The library is told to mount TapeX in DriveY and you see the tape being mounted. Next the server does a Test Unit Ready (TUR) to what he believes is DriveY and gets a response that there is no tape in the drive. Then the server issues an unmount command to the library which removes TapeX from DriveY. For DP you should use SCSI references instead of logical handles when you create the drives. I'd suggest verifying the devices that you have defined on the server are in the same order as the library.
I'm not sure if DP provides a wizard to autoconfig the libary (it does in Windows) but if so then I'd certainly run the wizard and let it setup the devices.
Let me know if this helps,
Glenn

Re: Linux backup across SAN

Brent DeGennaro — Tue, 22 Feb 2005 11:07:43 GMT

Glenn,

Thanks for the information. At this point I can't even tar to the tape in the drive but I'm not sure why.

$ sudo /bin/tar -cvf /dev/nst0 syslog
/bin/tar: /dev/nst0: Cannot open: Input/output error

$ ll /dev/nst0
crw-rw---- 1 root disk 9, 128 Mar 19 2002 /dev/nst0

Re: Linux backup across SAN

Bill Rothanburg — Tue, 22 Feb 2005 13:29:14 GMT

Check to see if the system recognizes the tape drive with the 'cat /proc/scsi/scsi' command. If the zoning, HBA bindings, and tape drive/library settings are correct, then you should see the tape drive listed.

You will see an entry like this:

Host: scsi1 Channel: 00 Id: 00 Lun: 02
Vendor: IBM Model: ULTRIUM-TD2 Rev: 29U0
Type: Sequential-Access ANSI SCSI revision: 03

You can also cat the /proc/scsi/lpfc/x to see if the HBA driver sees the tape drive/library. (replace the x with the scsi host number)

Re: Linux backup across SAN

Brent DeGennaro — Tue, 22 Feb 2005 13:31:21 GMT

# cat /proc/scsi/scsi
Attached devices:
Host: scsi0 Channel: 00 Id: 00 Lun: 00
Vendor: HP Model: Ultrium 1-SCSI Rev: E38W
Type: Sequential-Access ANSI SCSI revision: 03
Host: scsi0 Channel: 00 Id: 00 Lun: 01
Vendor: COMPAQ Model: NS ROUTER E1200 Rev: 0316
Type: Unknown

Re: Linux backup across SAN

Bill Rothanburg — Tue, 22 Feb 2005 14:30:30 GMT

Brent,

That leaves the question of device mapping. Most likely in the SAN or on the tape library.

You can use the "scsi_info /dev/nst0" to verify the device mapping on the OS. Since the cat /proc/scsi/scsi is showing only one drive, it's a pretty safe bet that it is correct.

If the tape is loaded, use "mt -f /dev/nst0 status" to check that the tape shows mounted and writable.

You can check the mapping in the Emulex with "cat /proc/scsi/lpfc/0" You will see the port and wwn of the connected device at the bottom of the output.

Hope this helps...

Bill

Re: Linux backup across SAN

Randy Weis — Tue, 22 Feb 2005 16:16:25 GMT

One other thing to check is the Storage Router. Has it been configured? Is it set to auto-discover or is on manual discovery? If on manual, go to the Discovery part of your NSR menu and click on discovery. If "Auto", reboot the router. Check your mapping when it is discovered, and make sure that your map, whether indexed or other, contains the host, the switch port for the router and the router WWN itself.

Re: Linux backup across SAN

Glenn N Wuenstel — Wed, 23 Feb 2005 08:46:18 GMT

Brent,
As was asked in the last post, in the NSR are you sure you've presented the same device that is defined on the Cell Manager?
What I'm getting at is that since you mention an ESL9322 I'm guessing that you have more than one drive. Depending upon your mapping you might be telling DP to mount to a different drive than you think. (It seems that I'm stuck on this idea)
But if you can provide the mapping and give information about your DP setup in general that would help.

Glenn

Re: Linux backup across SAN

Brent DeGennaro — Wed, 23 Feb 2005 13:10:03 GMT

Glenn,

You were exactly right. I straightened out my the mapping in my NSR and all is well. Thank you!

Brent