I ran HDTunePRO today and saw that my disk has a Current Pending Sector warning:
I read in wikipedia that the lower this attribute is the better and that it is a "Potential indicator of imminent electromechanical failure".
Should I be alarmed?
Pending sectors are a bad thing; a very bad thing. It means there is data on the disk that the hard drive is unable to read.
The drive wants to mark that sector as bad, and begin using one of the drive's space sectors to replace it. But it cannot do that until it can correctly read what is on that sector. It can't just give up on the data in that sector, because it means throwing away your data. So the drive retries a few time, before giving up - for now - and marking it as Pending.
If you happen to try to read what is in that sector (e.g. if you need to read part of a file), you will notice your system will stall for a moment (possibly up to two minutes), while the drive tries, and tries, (and retries, and retries) to read the sector - hoping it can get a good read.
Eventually you will see an event in your Windows System event log, from the Disk source, saying that the disk was unable to read that sector. You need to hope that either:
I wrote a much longer explanation here on SuperUser. I would repost it here, but people get grumpy when i try to spread upvoted helpful information.
Its common to have couple of sectors in current pending sector list - as long as the count doesn't increase rapidly in the new few days you should be fine
It sounds like the hard drive thinks two sectors are marginal but your reallocated sector count is zero so it looks like the two make get reallocated.
I like how wikipedia explains the two SMART parameters.
Also, keep in mind all drives will fail, so only backup the data you want to keep.