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2,397 bytes added ,  22:34, 2 December 2009
New page: A disk that I purchased new, and consolidated all my data to, actually ended up losing it's primary partition table and suffered from unknown other corruption and/or damage. Unfortunately...
A disk that I purchased new, and consolidated all my data to, actually ended up losing it's primary partition table and suffered from unknown other corruption and/or damage. Unfortunately, because real life has other demands and because I had a fairly recent backup and because I had undue faith in the drive, I did not have a current [[backups backup]] procedure in place to protect myself from data loss. So, I found myself investigating every known tool and technique for data recovery. The best tool I found was [http://www.gnu.org/software/ddrescue/ddrescue.html GNU ddrescue] ([http://www.gnu.org/software/ddrescue/manual/ddrescue_manual.html manual])

<pre>
root@hybrid:~# ddrescue -v /dev/sde /media/disk-a/backups/greg-laptop/recovery.img /home/greg/logfile

About to copy 160041 MBytes from /dev/sde to /media/disk-a/backups/greg-laptop/recovery.img
Starting positions: infile = 0 B, outfile = 0 B
Copy block size: 128 hard blocks
Hard block size: 512 bytes
Max_retries: 0 Split: yes Truncate: no

Press Ctrl-C to interrupt
Initial status (read from logfile)
rescued: 8157 MB, errsize: 1082 MB, errors: 97884
Current status
rescued: 8157 MB, errsize: 151 GB, current rate: 0 B/s
ipos: 160041 MB, errors: 298949447, average rate: 2 B/s
opos: 160041 MB
</pre>

== Other tools ==
* http://safecopy.sourceforge.net/ - similar to ddrescue, haven't tried it yet, so it may give different results
* http://www.knoppix.net/ - liveCD that includes many of the tools you'd need if you don't actually have another linux system
* [http://www.cgsecurity.org/wiki/Damaged_Hard_Disk#The_best_method:_Antonio_Diaz.27s_GNU_.27ddrescue.27 TestDisk] from cgsecurity.org recommends ddrescue for corrupted partitions. Still, it and photorec are very useful.
* [http://linux.die.net/man/8/gpart gpart] can guess PC-type hard disk partitions, but couldn't read mine (b/c my disk is too corrupted)

== Prevention ==
Maybe I should have used [http://www.cgsecurity.org/wiki/SMART_Monitoring SMART Monitoring]. The [http://sourceforge.net/apps/trac/smartmontools/wiki smartmontools] package is what you need to install, plus the [http://gsmartcontrol.berlios.de/home/index.php/en/Home GSmartControl] GUI if you're using a desktop system (instead of a server).

[[Category:System Administration]]
[[Category:Best Practices]]
[[Category:Hardware]]
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