topic Re: Tape drive issue on L2000 in Operating System - HP-UX

Tape drive issue on L2000

Kathleen — Tue, 04 Nov 2003 10:02:44 GMT

We have a tape drive that from time to time stops working. If we reseat the drive, and clean it, and run stm and check the drive, it will work fine.

Our tape bay has 2 slots for the drive. What I would like to do is swap the drive in the bay to the open slot. My question is, can I do this with the system powered on? The drive itself is hot-swappable, but moving the cables to provide power to the other bay, and the terminator and other cables. Will that cause a problem with the system being up and running? Just wanted to check before I did this.
Thanks

Re: Tape drive issue on L2000

Jeff Schussele — Tue, 04 Nov 2003 10:13:14 GMT

Hi Kathleen,

Yes you *should* be able to get away with this. Note that you'll certainly get SCSI lbolt errors when the tape drive and cable are moved, but this should not be fatal.
Note also that most enclosures have a SCSI ID switch - make sure these match or you'll have to ioscan for the tape again.
BTW - I've had bad enclosure slots on 5300 tape array positions before, so this is not unheard of.

Rgds,
Jeff

Re: Tape drive issue on L2000

Joshua Scott — Tue, 04 Nov 2003 10:21:41 GMT

Intermittent problems can be a sign of a bad slot in your array (I assume you have a so-called "SMART" enclosure, based on your message)

You may also want to check the cable length. Most tape drives are Single-Ended, and if you are using an LVD port on the server to connect to the back of the enclosure, make sure that the cable length doesn't exceed 3.0 meters.

Keep in mind that each device will eat up 0.5 meters of that length, so if you have a 2.5 meter cable (which is fairly standard) you may be on the edge of the allowable cable length, which may cause your issues.

-Josh

Re: Tape drive issue on L2000

Steven E. Protter — Tue, 04 Nov 2003 10:25:00 GMT

Tape drives are not genreally hot swappable.

You can do a cable switch while the system is running.

I however take the extra precaution of shutting down the system before doing that stuff. Its all about risk tolerance. Our tape drive cost $5K, the system cost $30K so why take the risk.

If a hot swappable disk fails I do do that hot, because its specifically designed for that.

What you are planning won't help your tape drive. You need a hardware service call on that.

SEP

Re: Tape drive issue on L2000

George_Dodds — Tue, 04 Nov 2003 10:30:57 GMT

I have the pleasure of 1 external dlt80 and 3 L2000's to back up with it.

Network backups take too long so i've just been swapping the drive between the servers for the past 2 years without any issues.

Not the best way to do it but it works!

Cheers

George

Re: Tape drive issue on L2000

Sanjay_6 — Tue, 04 Nov 2003 11:24:15 GMT

Hi,

I would suggest you shutdown the system before swapping cables. Since the driver is hot-swappable, you can get aways by removing the drive, but removing the cable and moving the drive and cable to another bay is not something i would suggest when the system is online.

Hope this helps.

Regds