Finding replacement for Cache-A that works with existing media server

[Jack Mcgee]

Our Cache-A started exhibiting many errors. I used the Cache-A machine to restore TAR tapes. Our internal LTO drive was apparently good. I put a live Ubuntu installation on USB stick, plugged it into front of Cache-A. Plugged a NTFS formatted raid drive onto USB in back. That drive mounted at /media/ubuntu/CacheARestore

Booted off the Ubuntu USB, it detected the internal LTO drive. I used the CAT DV tech note to restore the TAR tapes. VERY slow process, but it works. You have to rerun the command maybe hundreds of times to restore all the files. But it does work.

the command I used:
sudo tar xvf /dev/nst0 -b 300 -C /media/ubuntu/CacheARestore

Eject:
mt -f /dev/nst0 off

Rewind:
sudo mt -f /dev/nst0

I’m not aware of any other way to restore the TAR tapes, other that a current day Promax solution.

[Deleted User]

Jack,

Thanks for the quick reply however I’m not looking to recover tapes with errors. All my backups minus the most current are good. I’m looking for a replacement LTO drive that will work with existing server connections, Win Server 2008 OS and is compatible with CatDV. The big bonus is if the replacement LTO unit will read LTO-5 TAR formatted tapes as well.

Any thoughts?

Lee

[Jack Mcgee]

We didn’t have any tapes with errors. I was only speaking to your “bonus” point.

There is only one machine out there that will read those TAR tapes. I think that is the new Promax LTO machine.

If you don’t buy a Promax machine, you have to use the commands I gave or similar, to restore the TAR tapes.

We went with 1 Beyond LTFS solution with CATDV bundled. It can’t read the TAR tapes.

[Tom Goldberg]

In fact any linux or unix machine with an appropriate mounted LTO drive can read Cache-A tar tapes.

The general form is to issue the command Jack wrote in his previous post, although this can be automated with the command:
while [ 1 ]; do tar -xvf /dev/nst0 -b 300 -C /media/vtape/restore_directory/; done
Full instructions for doing so may be found at Reading Cache-A Tar Tech Brief.

I would note that if a Cache-A unit serves your environment (as it sounds like it does for Lee) there is no reason to stop using it just because ProMax is dropping it. Errors occurring during backups are due to correctable causes:

Make sure your source drive(s) have a reliable route to the Cache-A – sometimes errors like these are just a bad ethernet cable or switch

Run a cleaning tape to eliminate the possibility that this is just due to dirty heads

Run fsck on the Cache-A file system to detect and correct file system errors. You can also run the smartctl commands to check on the health of your disk drives. (any linux guy can help with these or contact me for instructions)

Run HP tape tools analysis to check on the health of the tape drive (installed on every Cache-A – run by issuing the command /opt/ltt/hp_ltt) – replacing the tape drive is much less costly than buying a whole new system

Tom Goldberg
TGCS
30201 Rainbow Hill Rd.
Evergreen, CO 80439
mailto:tomgoldberg@gmail.com
https://tomgoldberg.net

[Deleted User]

Thanks Tom,

That helps a lot!

Lee

[Deleted User]

Tom Goldberg

I finally was able to attempt to run FSCK from the Cache-A terminal app. When I did, I got a warning

“Warning!!! The filesystem is mounted. If you continue you ***WILL*** cause ***SEVERE*** filesystem damage.
Do you really want to continue?

Of course I replied ***NO***

Knowing little to nothing about Unix commands, would you mind letting me know how to proceed?

Lee

[Tom Goldberg]

Hi Lee

I’ve never seen that warning, perhaps you tried this with your server mounted? Disconnect any source volumes.

The command you should run is fsck -C /dev/md0

If that still gives you such a warning, or if you need further assistance, please contact me by email off-forum and I’ll try to help you out.

Tom Goldberg
TGCS
30201 Rainbow Hill Rd.
Evergreen, CO 80439
mailto:tomgoldberg@gmail.com
https://tomgoldberg.net