Problems with Backup Drives

[Dave Greenhow]

To save myself some embarrasment, i am a complete newb at this set up and we have been left in the proverbial you know what.

At present we have 4 machines that are connected to an MSL6000 via a brocade fibre switch.

The tape drive has two backup drives (1m and 2m)

When we perform an ioscan, we get the following outputs

1 of the machines has claimed both drives
1 shows that 1m has NO_HW, but claims the second drive
The other 2 do not see the hardware path

Could anyone point us in the right direction of
a. Where to begin trouble shooting and
b. Other places to pick up information regarding problems like this

Many thanks

Dave

[melvyn burnard]

I would suggest you start by investigating your SAN layout and configuration, sounds like your switches are not allowing things through

[Dave Greenhow]

Thanks for the prompt reply.

The switches do have zoning implemented on them, but the backup zone covers all drives and machines off. Do you have any thing I can try to resolve (makenod, etc)

Cheers

Dave

[melvyn burnard]

If devices are showing up as NO_HW, or not even showing using ioscan, then using mknod is of no use. It tells you that the hardware out there has either been visible to the system and now is not, or it is just not visible.
it sounds like you may have a zoning issue

[James A. Donovan]

It most likely is a zoning issue at the switch, that said, I think a better question would be why do you want all 4 machines to be able to see each drive? It's can be a good thing to allow multiple machines access to disk drives, but multiple machines being allowed simultaneous access to tape drives can be very, very bad. You don't want one machine backing up it's data suddenly pre-empted by another that thinks it's data is more important. Unless you have fairly sophisticated backup software, it's probably a better idea to just let one or two machines control access to the drives.

[Mark Greene_1]

I'd reverify the zoning. Make sure that the current config is active, not just saved. I'd also rum fcmsutil on all of the fibre cards. run with and without the stat option:

fcmsutil /dev/td0

fcmsutil /dev/td0 stat

and validate the setup and check the error counts.

mark

[Gennaro Tarone_2 · Accepted solution]

It definitly sounds like a zoneing issue with the brocade switch. We use Brocades Web Tools to configure & view our Brocade switch configs. Check it out at this link:
http://www.brocade.com/san/pdf/datasheets/WEBTOOLS_DS_06lr.pdf or do a search at brocades web site. It sounds like you want just one zone with all servers & drives in that zone. But as stated above. This is not the best config since data may get over written etc.
Back to your problem does's the brocade have links with all your servers? Whats the links status? You may have these ports turned off but configured in the zone. Again check the brocades switch settings. As for the servers that do not show the drives you will need to do a insf once the drives are seen. As for the server that has NO_HARDWARE for one of the drives it did see the drive before but doesn't see it now. Someone may have messed with the brocades config for this to happen. Also does the servers have the prober drives loaded? Do an ioscan -fn | more & check the hardware path to the brocade. Do the serves see the brocade? use SAM to check & make sure the stape driver is loaded. If the servers do not see the brocade compair the system that does see the tape drives with those that do not. You may need a hardware enablement patch. More than likly its sounds like a config issue on the brocade itself.

[Dave Greenhow]

Hi, I have checked the zoning on both switches (we have fail over) and the port on switch 2 differs from switch 1.

On switch 1, the port is online and is set to F.
On switch 2, the port is disabled and is set to U.

Both ports are linked via aliases to our NSR card which resides in a MSL6000.

Is there a possibility that the two that cannot see the paths at all have failed over to the second switch? and as it is disabled, cannot see the tape drives? is there any way i can check this?

[Mark Greene_1]

The "U" status on the port means that nothing has logged in, but that it's up and ready.

Had you looked at the event log for both switches? If there was a drop from the first switch you should see it there.

mark