checking tape backups

[helpdesk2005]

hi i have a tape drive from sun that uses dds4 tapes that is connected to my cms/pbx. i want to know how i can go about reading and checking these tapes. i have no unix experience and any commands or such would help. thanks.

 

[KenCunningham]

It would be helpful if you could indicate how your backup is made, ie what command, tape drive etc (you may be able to find this in the script used to back up the syatem). Basically, for a list of what's on the tape(s):

mt -f <tape device> rewind - to rewind the tape to the beginning

tar tvf <tape device> - if tar

cpio -itv < <tape device> -if cpio

ufsrestore -tvf <tape device> -if ufsdump

Of course it may be that your backup is made by some bought-in solution, in which case we'll need more details, please. Then of course there's dd....

Post back with your findings or further questions.

 

[helpdesk2005]

hey ken thanks for the feedback - the backup is being done by cms (call center management software). The tape drive is an hp dd4 tape drive. Not sure if this helps you out or not. thank you.

for the <tape drive> what is replaced by that? is it a drive letter? how do i list the drives on unix? i'm a windows geek sorry

 

[KenCunningham]

Hi. Assuming that this is a 'standard' Solaris OS (on which your software sits, I imagine?), the tape device is usually something like:

/dev/rmt/0 (for native data)

/dev/rmt/0c (for compressed data)

It may be that the 0 (zero) will be a 1, depending upon how many tape drives you have attached, but the likeliehood is that it will be 0.

Do you have access to the script the cms uses for the backup?

 

[daFranze]

btw: I suggest to use /dev/rmt/0n or 0cn
n is the nonrewinding tape, if the tape contains several backups the tape won't be rewound after reading the first backup; if you want to read the second tapefile use
mt -f /dev/rmt/0n fsf 1 # "fastforward one file"

Best Regards, Franz
--
Solaris System Manager from Munich, Germany
I used to work for Sun Microsystems Support (EMEA) for 5 years in the domain of the OS, Backup and Storage

 

[helpdesk2005]

i only have 1 tape drive and unfortunately i don't have access to the script. in terms of tape being rewinded i am not sure..so should i be including the "cn" to the 0?

when i run this command will it execute anything in terms of write and change? unix really freaks me out and this is the system that holds all of our critical data and of course don't want to mess it up...mind you i am logging in as root as well....yikes...

 

[daFranze]

as long as you don't write to the tape you can't destroy anything...
Well, I suggest to use 0cn, since tape won't be rewound after reading the first tapefile...
Did you find out how cms wrote to tape (using ufsdump, tar, dd, cpio ...)?


Best Regards, Franz
--
Solaris System Manager from Munich, Germany
I used to work for Sun Microsystems Support (EMEA) for 5 years in the domain of the OS, Backup and Storage

 

[KenCunningham]

As additional protection, make sure the write-protect tab on the tape is at the read-only position ;-)

I'd be interested as to whether you came to any conclusions as to the backup type too.