The 500GB Seagate ST9500420AS (D005SDM1) hard drive in my 2011 Dell XPS 15 crashed the other day and, although I had the most important data backed up, I would really like to save the rest of it. It had been running Fedora (23, I think), had 3 ext4 partitions and 1 swap partition. I would be grateful for any tips on how I could access the partitions.

So, when I boot the computer I get the following error:

Operation system not found.

The BIOS diagnostic tool gives the following error:

Error Code 0147. Msg: Error Code 2000-0147. Msg: Optical Drive 0 - self test -- OPU failed.

I booted the computer from an Ubuntu 17.10 live USB stick and received a lot of kernel errors about the hard drive. The syslog is here: https://www.dropbox.com/s/86kyicthla8k367/syslog.txt?dl=0

There seems to be some kind of an input/output error, but Google hasn't got me anywhere yet. When I run Gnome Disks, it displays the disk as "500 GB Unknown" and no partitions, but in the "Assessment" field it says: "Disk is OK,one bad sector". (Screenshot: https://www.dropbox.com/s/b0fqe5vrwlc90gz/hd_problem.png?dl=0)

If I try to make Disks create an image, it says that it's unreadable and replaces the data with zeros.

If you have any ideas on how I could access the data again, I'd be really grateful.

2 Answers 2


It's iffy, the HDD might be too far gone, but suppose it's not. The preferred method is to use a low level tool to back up whatever readable parts are left to a bigger hard drive, then look for any needed files on the backup. Sometimes a 2nd copy of the backup is needed, (to run fsck without risk, etc.), so the bigger hard drive should be at least twice as large, (i.e.: 500GBx2=1TB or more).

Linux tools for backups of balky HDDs include command line tools like ddrescue and safecopy.

  • Thank you for that. I'm reading the documentation for these tools. Any tips on command line parameters for ddrescue that might be helpful in this case?
    – Olaf
    Oct 26, 2017 at 18:13
  • @Olaf, Just try the default and see what happens. (Make backup with ddrescue, make 2nd copy of backup, if needed run gpart on 2nd copy, then run fsck on 2nd copy, then mount 2nd copy, and look for files.) Since there already exist good backups of most of the files on the disk, the copy needn't be perfect. With luck the corrupted files may turn out to be those that were already backed up.
    – agc
    Oct 26, 2017 at 19:33

well, the disk is either dead or failing... try this if basic software diagnostic fail (ie: if a dd from the disk work, probably the disk is good):

If data is really important, it may be better to send the disk to a data recovery company, they are expensive, but they can replace failed parts and save data that no other method can.

If not that critical, you can try to recover yourself... if the plates motor died, you are out of luck, even trying to replace without a clean room is very hard, many people that open and close modern disks report they fail to work after. If all components are in a minimal working state, get a new disk or at least enough free space to image the all disk. I also use a external USB or eSATA external disk connector, so it is simpler to connect and disconnect and keep cool and under control. USB is slower, but can be enough to save a few files. usb3 or eSATA is recommended for a full disk image

Place the HD in a sealed plastic bag and place it in a freezer. The idea is to cool it, as low temperature can help both the motor and electronic components. So after some hours, take the HD, clean it with a dry towel, to avoid water condensation (keep checking for the first minutes) and connect it to the computer. Be ready to have a working storage to either dump the disk or the critical files. turn on the computer and pray... if it works, mount any filesystem read-only and try to copy the critical files. if it fails or after that, you can try using ddrescue to make a image or dump the partition to another disk, that you can later use recovery tools. DO NOT TRY TO RECOVER FROM THE BROKEN DISK! the disk is probably just working for a few minuted and any change may make everything worse.

So with with the working disk, the heat will slowly increase and the disk probably start failing, so you may need several tried to slowly recover or finish the image. ddrecue can start from any disk position and even start from the end to the begin. So after you have a image or a duplicated disk, you can try to recover... if data is important, make backup of the image, so you can try with several programs if needed.

testdisk is a good program to recover data. If partition are in a good state, you can even fsck the image and try to mount it again and even reuse-it... if not, recover what you can using what is detected.

there are other tools that can help, check this page: https://www.journaldev.com/36900/top-best-linux-data-recovery-tools

IF the cold HD still fails, you are probably out of luck, the report you said looks like the basic electronic components are working (the disk is detected), if still fails to be detected and accessed, some important component failed and probably only professional service can help.

PS: also, learn from this experience and setup a backup system for critical files. Cloud backup is easy, but using DVD, external HD or other computers are good alternatives. Mirrored (raid or similar) can help, but isn't a backup. learn how to do offline backup.

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