Ubuntu – What to do if Disk Utility shows bad sectors pending in SMART

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I have 12.04 32bit installed on my hard drive. Ubuntu is the only OS. I recently installed it after getting rid of Windows 7. When I run Disk Utility under SMART Status it says "disk has a few bad sectors", so I clicked on View SMART data and run self tests. I run the extended SMART self-test and it only takes 5-10 seconds for it to stop and reads Self-Tests: FAILED (Read), Bad Sectors: 1 bad sector, Overall Disk Assessment: Disk has a few bad sectors.

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Is this something I should be worried about?

Best Answer

At this point in time I wouldn't. Hard Drive manufacturers, normally pack spare sectors in the drive just for situations like this. Keep an eye on it, and always have a backup of your data handy. Also I would suggest that you run the manufacturers diagnostic tool, and that can be acquired form the drive manufacturers website. Once you do that, and it gives you an error code, and providing htat the drive is still under warranty, then call the manufacturer,and get it replaced.

Important note to keep: Disks that start with 1 bad sector, will probably get worse. I can't stress enough the importance of a backup.

Related Solutions

Ubuntu – Is Disk Utility reliable

Yes, it is reliable. Run sudo badblocks -b 512 /dev/sda to scan the disk and find where the bad sector is. It will show the number of the bad sector. You can then verify it with:

sudo dd if=/dev/sda of=/dev/null iflag=direct bs=512 skip=sector_number count=1

Make sure you type the command exactly as stated, using the correct sector_number from badblocks. This should fail with an IO error ( since the sector is bad ). If it doesn't, then you got something wrong. If it does, then you can proceed with trying to repair the bad sector:

sudo dd if=/dev/zero of=/dev/sda oflag=direct bs=512 seek=sector_number count=1

After that, check the SMART status again and the pending_count should have gone down. If the reallocated_count is still zero, then the disk is fine.

Ubuntu – Difference between SMART reallocated sectors and bad sectors

Your guess is right. The drive only reallocates a sector when a write operation fails. Check wikipedia. Also take a look at the Current Pending Sector Count S.M.A.R.T attribute. The pending sectors are those which had read failures but no write failures, upon writing to these sectors the sectors will be reallocated.

The OS would know nothing about a remapped sector, because remapping is transparent, this means that is the OS try to write to a sector e.g 27643 and that write fails, then the drive will remap the sector internally to another physical area. Then when the OS tries again to write to sector 27643 it will succeed. The OS doesn't know that it is writing to a different physical area.

Best Answer

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Ubuntu – Is Disk Utility reliable

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