After working for a while, my filesystem (EXT4) becomes read-only. I then use my live USB to boot into live mode and I run fsck on the corrupted partition (and others too, to be safe). I run fsck -y and it does fix all errors on the problematic partition. When I run fsck, again, all partitions are reported as clean.

Then I reboot normally (not live USB) into my system; I run a few touch abc commands at different locations, to test and it is able to write to disk. After a while however, it again becomes read-only.

I've repeated this entire process 4-5 times (fsck-from-live-usb --> boot-normally --> becomes-read-only --> fsck-from-live-usb), and I don't know the cause of this problem.

dmesg shows the following kind of errors:

blk_update_request: I/O error, dev sdb, sector 2521582056

tag#28 FAILED Result: hostbyte=DID_SOFT_ERROR driverbyte=DRIVER_OK

Is there a way to fix this? I'm unable to work on my system. It doesn't look like a hardware problem, since fsck fixes everything and smartctl also reports the drive to be okay, no errors.


  • 1
    Can you post the output of the smartctl -a /dev/xxx to a pastebin site and link here? – Miuku Jun 17 '18 at 15:29
  • @Miuku pastebin.com/LKjEvWQ9 – sanjeev mk Jun 17 '18 at 16:17
  • Your SMART output looks fine. I would replace the SATA cable as the first thing. Then move the drive to another SATA port to make sure neither the cable or the port are somehow causing issues. – Miuku Jun 17 '18 at 16:23
  • As we have said before, one of the classic large-scale investigations into smartctl results concluded that if smartctl says your dirve is failing, it probably is; but if it says it's fine, you can conclude nothing. That is, it's a good predictor of failure, but a poor predictor of longevity. If you suspect this drive - and I would if I were you - replace it immediately. Your data are too valuable. – MadHatter Jun 18 '18 at 6:38

While SMART reports all OK, the disk may be bad anyway, you should try to:

  • perform a SMART test with smartctl -t long /dev/sdb, see for example the Arch wiki
  • check the disk for badblocks with badblocks -s, for other ways to do it (some destructive) see (again) the Arch wiki

It may also be a problem with the SATA controller or with the bus, but first you should check the disk (maybe from another machine if you are not sure about the controller).


This is most likely a bad block. While my company has a rule that any such hard drive should be discarded immediately, we, home users, often try to salvage as much as we can. The tool of choice is HDD Regenerator (non-destructive), but it's paid software. If you want to do it for free, you can use HDD Low Level Format. Old versions are free. This will require a complete backup and restore. The programs I mentioned work independently of the filesystem. HDD LLF runs on WinXP or 2003 directly, whereas HDD Regenerator creates a bootable USB drive, but is also available online as a Linux initrd floppy image used with memdisk.

  • 1
    Can I ask why the downvote? I have used the solution I proposed successfully in the past. – Zdenek Jun 18 '18 at 16:55

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.