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Today I was working when all of a sudden a power loss (in the entire house) occurs.

I tried to reboot the machine but it states that there's an "Ebios error"; tried with an Ubuntu 9.04 live cd and while booting it states that there are various I/O errors on the first partition (the one with the boot sector).

Now I managed to backup all of my data (using the live cd aforementioned) but I don't know if it'll worth the hassle of a reinstallation (and if it could do something useful) or if the only thing to do is to drop the hard disk as far as possible...

Thanks in advance.

EDIT: It was a very fast shutdown, but the power came back after 5 minutes or so (so very gently)...but the disk is definitely damaged!

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up vote 7 down vote accepted

Power loss CAN damage a harddisk, but it would be unlikely, yet if you feel uncomfortable or just want to be a 100% sure, consider buying yourself a fine brand new hard drive... The fact that your harddrive is giving you I/O messages isn't a good sign anyway...

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Actually I found it strange, yet its behaviour led me to think about a mechanical damage (when it's booting, during the I/O errors, it makes a strange noise, as if it was searching again and again in the very same sector). – dag729 Jun 16 '10 at 20:48
It's quite possible that is has mechanical damage... – BloodPhilia Jun 16 '10 at 21:04
Its probably more likely that the powerloss caused the drives Master Boot Record, or other information that tells the system where various data is to be corrupted. If the data was being modified when the power went out, the data may not be in a consistent state, hence the IO errors. I've heard drives with corrupted MBRs or FATs make strange noises. Unless you can repair the corruption, you're looking at a reinstall anyway, disks are relatively cheap these days, I'd recommend a new disk to be safe. – BillN Jun 16 '10 at 22:59
Hey, if you're just going to toss that drive without testing it, let me know. Picking up a possibly healthy drive for just the cost of shipping strikes me as worth checking out. ;-) – irrational John Jun 17 '10 at 15:47
@irrational John: you are not really meaning it, trust me! :D – dag729 Jun 19 '10 at 22:34

We've found that in many cases it isn't the power loss that causes the problem, it's the power surge that happens when power comes back that can cause problems. Not all power strips are created equal in this regard.

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Power loss shouldn't do any physical damage to the disk, as most modern disks use the inertia of the platters to safely park the head when they suddenly lose power. However, depending on why the power went out (power surge tripping breakers, for instance), it's possible damage was done that way, or if the PSU in the machine reacted badly to losing power.

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I agree with my understanding of what all the previous answers are saying.

  • Sudden power loss is very unlikely to physically damage a hard drive. While anything is possible, this sure doesn't seem probable.
  • Sudden power surge, possibly could cause hard drive damage. But this also not the most likely failure mode.

What is more likely IMO is that the file system on the drive might have been corrupted. The likelihood of this increases if you are using an older file system which does not support journaling such as FAT or FAT32.

I think it is more likely that damage, if it occured was to the file system rather than to the Master Boot Record (MBR) of the drive. The MBR is read from rarely and written too even less often. So it seems more likely to me that you damaged the file system than the MBR.

You do not say which operating system was running and what file system it uses. These are potentially important pieces of this puzzle.

While checking out the drive with a hardware diagnostic program is a good idea, I would probably start by running a file system integrity check. If you are using windows then run CHKDSK.

If the problem is happening on your boot drive or partition you may need to boot from your install media to verify the file system.

In any event, I hope you had a current backup of any data on the drive which you value.

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You're right, although I'm almost certain at this moment that the hard disk is really broken. I was using HFS+, journaled, so unlikely to be corrupted, even though it can be. Thanks anyway for your precious advices! :D – dag729 Jun 18 '10 at 10:26

if power loss happened when the moment of data writing to the hdd that should make a damage to the hdd so you should try a different hdd to see if this is the problem but i'm guessing that ebios error not related with hdd if that error message not about S.M.A.R.T. should use a ups to avoid this kind of power losses or surges ((and it should be quality product it can be very useful when this kind of situations))

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It's almost impossible for power loss to do more than corrupt a sector.

However it's possible for a drive to fail in a fashion that allows it to continue to work but fail on the next boot. Just last week I had a drive brick itself during a normal reboot--I'm sure it didn't actually die at that point, but rather something went wrong that it wouldn't respond properly to initialization commands in the days before this happened. Reboot, the system looks for what drives are out there and the drive doesn't answer.

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Download a HDD diagnostic utility from the HDD vendor or something like HDDScan. Check the S.M.A.R.T. report, perform the S.M.A.R.T. and storage verification test. That should give you a pretty good idea of what is wrong.

Given that the errors are local to certain partitions rather than just random I/O failures as one would expect from circuitry damage (which is the most-likely type of damage from sudden powerloss or hard reboot), it's possible that you could simply be data-level damage, e.g. corrupt partition table, MBS, or filesystem.

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