Re: [Bug-ddrescue] ddrescue hd->tape restore from tape?

[Steve Costaras]

Problem with TAR is that it's a filesystem level backup utility not a block level, in my case I did a mke2fs over the existing filesystem so there is nothing there for tar.    And yes the old method of doing a dd piping to tar would possibly work it's not reliable as the standard dd has no error recovery (same reason why you probably wrote ddrescue).

Due to the size of the volume that I'm trying to recover I do not have another volume w/ ~6TB of space on it for an image file so the only option I have is writing to a tape drive.   

At this point it appears to be working (ie, ddrescue v1.2 is sending the data to the tape drive and I'm working through the tapes/changing them each time ddrescue reports output location is full (tape full).   

My question is more to if/when I need to re-lay down the raw blocks back to the array to try a second recovery attempt would setting the output block starting point be the method I would need to use?   I'm assuming it is which is why I'm saving off each of the logs from the ddrescue to give me the start/stop point from each tape and it's related disk block, but since, as you pointed out, not many people seem to be doing this or at least providing any experience with it to see what's right/wrong.

Unfortunatly the other tools that I've looked at all have various problems (aimage, air, dd_rescue, et al) yours compiles fine and can at least write to a tape directly.

Steve




-----Original Message-----
From: Antonio Diaz Diaz [mailto:address@hidden
Sent: Saturday, October 21, 2006 05:25 PM
To: 'stevecs'
Cc: address@hidden
Subject: Re: [Bug-ddrescue] ddrescue hd->tape restore from tape?

I am no expert in tape backup but I think you should use a backup 
program, like GNU Tar, to write the tapes and use ddrescue only in case 
a tape gives read errors when restoring data from it.


Regards,
Antonio.