Re: Star single file restores

Dan <[email protected]> wrote:

> Every weekend, I back up 1.1TB, about 10 million files, onto a tape.  Yes, all on one tape.  The backups work great!
>
> The problem is that a user will delete one of their files, and I need to restore it.  Scanning the tape from the beginning to the end takes about 4 hours to restore a file.  Using "mt -f /dev/nst0 fsr nblocks" works really fast.  Testing with mt, it takes 5 mins to fsr to the end of the tape.
>
> I see in the man page the option for -block-number to show the relative location of each file on the tape.  Using mt to put the tape in the right spot works nicely, but when I use star to start the extract, it says "star: Unknown archive type (neither tar, nor bar/cpio)."
>
> I can't find any mention in the man page how to tell star what the starting block number should be.  Is there something else I'm missing?

star prints block numbers based on 512 byte units in this case.

"mt fsr" will forward tape blocks which is 10 kB if you do not specify a 
different size. You would need to tell star to run in -i mode to find the next 
file after you did fsf to something slightle before the block you like.

Be careful on Linux, Linux does not behave like UNIX here.

If you run incremental backups, you would need to create a database that tells 
you on which incremental the desired file is located.

Jörg

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