Very Slow Advanced Scan

How to use TestDisk to recover lost partition
Forum rules
When asking for technical support:
- Search for posts on the same topic before posting a new question.
- Give clear, specific information in the title of your post.
- Include as many details as you can, MOST POSTS WILL GET ONLY ONE OR TWO ANSWERS.
- Post a follow up with a "Thank you" or "This worked!"
- When you learn something, use that knowledge to HELP ANOTHER USER LATER.
Before posting, please read https://www.cgsecurity.org/testdisk.pdf
Locked
Message
Author
johnywhy
Posts: 4
Joined: 19 Mar 2015, 01:31

Very Slow Advanced Scan

#1 Post 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!

User avatar
cgrenier
Site Admin
Posts: 5432
Joined: 18 Feb 2012, 15:08
Location: Le Perreux Sur Marne, France
Contact:

Re: Very Slow Advanced Scan

#2 Post 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.

johnywhy
Posts: 4
Joined: 19 Mar 2015, 01:31

Re: Very Slow Advanced Scan

#3 Post 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 1814 times
gparted3.png
gparted3.png (49.48 KiB) Viewed 1814 times
ddrescue.png
ddrescue.png (22.33 KiB) Viewed 1813 times
thx!

johnywhy
Posts: 4
Joined: 19 Mar 2015, 01:31

Re: Very Slow Advanced Scan

#4 Post 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

Locked