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Very Slow Advanced Scan

Posted: 19 Mar 2015, 01:40
by johnywhy
Hi

I have a hard disk that recently went bad. Running quick scan runs quickly, but the advanced scan is taking so long it looks like it will take about 2 months to scan the whole drive.

I'm thinking the scanner is RETRYING multiple times, or has a long timeout value. Clearly, the cylinders are bad, and there's no advantage to constantly retrying.

Is there a way to change the number of times the scanner tries, or change the timeout value?

thx!

Re: Very Slow Advanced Scan

Posted: 19 Mar 2015, 08:09
by cgrenier
Try to clone the disk to a new empty disk using gnu ddrescue
http://www.cgsecurity.org/wiki/Damaged_Hard_Disk
Once the copy is done, remove the original disk and try TestDisk again on the clone.

Re: Very Slow Advanced Scan

Posted: 21 Mar 2015, 15:04
by johnywhy
But, can i clone a disk that cannot be mounted?
or, how can i image a partition that cannot be mounted?

ddrescue doc says "only mountable device formats can be rescued with ddrescue."

gparted can see it, but cannot mount. see attached pictures.

however, when i ran thee following command, ddrescue DID begin to image the entire drive. Is this process doomed to fail, since the partitions cannot be mounted?

Code: Select all

ddrescue -d /dev/sda /mnt/sdc1/ddrescue/asus3-21.img /mnt/sdc1/ddrescue/asus3-21.log
attached pic shows this process happening in terminal window.
gparted2.png
gparted2.png (41.15 KiB) Viewed 1841 times
gparted3.png
gparted3.png (49.48 KiB) Viewed 1841 times
ddrescue.png
ddrescue.png (22.33 KiB) Viewed 1840 times
thx!

Re: Very Slow Advanced Scan

Posted: 21 Mar 2015, 21:22
by johnywhy
seems to be working, but taking forever. i only need to recover that one partition, not the whole drive.

can i use the "First Sector" value as-is for the ddrescue -i option? Or do i need to divide by 8 or 512 or something?

thx