"Reallocated sector count has increased" email notification

Reallocated sectors are the HDD moving information from a damaged sector to an undamaged sector. This can happen from normal usage of the disk and small numbers are normally not something to be too concerned about. When they start growing in number rapidly is grounds for concern. As the drives were purchased separately you may want to check with Seagate to find out what the warranty replacement policy is for them and how many sector reallocations are within tolerance.
I would highly recommend regularly backing up your information.

Thanks alot for the explanation what the error I am seeing is. Am I safe assume the data is successfully moved from the damaged sector to the undamaged location such that as on subsequent back ups, I will not have LOST any data (like during the reallocation)?

BTW, ballpark-wise, how much data are we talking about when the 18 sectors reallocated occurred?

Since this disk is listed on the ReadyNAS compatible list, I assume someone around here knows (at least general) the expected 'tolerance' question you recommend I ask Seagate. I will wait a week or so to see if someone can post it here since I am preparing for an out-of-town trip starting tomorrow for a week and do not have much time to spend on this at the moment. I will try to sneak in a call to Seagate this week, if possible.

You are correct, that count is successfully reallocated sectors. Each sector on that drive is 512 Bytes.

Just an update. I called Seagate tech support today and the rep says I am still covered by warranty and provided me a case # and connected me to the warranty group's phone que. Because I was in transit today, I hung up to the music after about a ten minute wait. I will attempt to submit a warranty request shortly (www.seagate.com/warranty).

One interested thing the tech rep stated - that the reallocated sector error does NOT mean data was relocated from bad to good sector(s). He claims data could have been lost or corrupted.

Any comment on this statement?

I could see how you could lose data to a reallocated sector when using a single disk. One of the benefits of using a RAID is that you can have parity spread out across your drives so that in most cases loss of an entire drive wouldn't cause actual information loss. What RAID do you have setup on your Pro Pioneer?

winger wrote:
.One interested thing the tech rep stated - that the reallocated sector error does NOT mean data was relocated from bad to good sector(s). He claims data could have been lost or corrupted.

If the reallocation is done in response to a read error, then the data is corrupted (since it could not be read). In a redundant Raid array the data should be automatically recovered.

readysecure1985 wrote:
I could see how you could lose data to a reallocated sector when using a single disk. One of the benefits of using a RAID is that you can have parity spread out across your drives so that in most cases loss of an entire drive wouldn't cause actual information loss. What RAID do you have setup on your Pro Pioneer?

I am running X-RAID2, 4 disks with dual redundancy. I do not recall all the details (it's been two years since I set this bad boy up), but I think this setup allows any two disks to die and I still have all my data intact. Is this correct?

Is there a relatively easy way to pinpoint what sector got reallocated and 'see' what data this involves (in turn, see if the data is corrupt OR it got moved successfully) ?

Just a note - I took a gander at the seagate.com/warranty page just now. It looks like I may still have to run a diagnostic against the disk in question using Seagate's tools before I can submit the disk for a warranty replacement. Does anyone have experience with this part of the warranty process? IF I am getting the Reallocated sector error email from the RNPP, does this mean Seagate's tools will find same issues?

-you can schedule a "Disk Scrubbing with Auto Parity Fix" through Frontview (select volumes, then the volume maintenance tab). This could also find more failures (since it will read everything).

-If you still have 17 reallocated sectors, Seatools will likely pass. Disk manufacturers and customers often have different thresholds for replacement. Netgear usually suggests 50 reallocated sectors. Though once the number starts growing, I've found that the drive can degrade very quickly.

-Since Seatools only runs on Windows, Seagate doesn't actually require you to run SeaTools. There are several failure codes you can manually enter during the RMA process, there is a list here: http://www.seagate.com/staticfiles/supp ... codes.html. I have used 659DC7AE successfully.

-Seagate will give you a refurbished "equivalent" drive, which might not be on the hardware HCL. They have been somewhat flexible with me - once I didn't feel that they sent me a comparable drive and they reviewed their inventory and gave me some other options. If you live in the US, use their advanced replacement procedure - the shipping costs are reasonable, and you get the drive much quicker. It is also reasonable to buy a new retail replacement, and keep the refurbished drive as a spare.

I have these same drives in my NV+ and after a few months of ownership started to see these errors on one drive over a few weeks. After a month or two the drive "settled-in" at 23 reallocated sectors (zero on any of the others), and now a couple years later this drive remains at 23 sectors reallocated i.e. no further errors. At the time I'd bought a spare drive to have on hand, and I still have the spare in the static-free bag.

I've had zero data loss AFAICT, and will doubtless leave the drive alone unless-or-until it starts acting-up again. Seems to me I read somewhere that 100 sectors was Bad, but I'm sure this is all subjective.

I do of course back-up my NV+ to an external hard drive.

Netgear's advice is here: http://www.readynas.com/kb/faq/hardware ... e_last_day

There is of course some subjectivity involved. Reallocated sectors will hurt transfer performance, since there is more seeking. People have different risk tolerances, and of course consequences for unavailability vary as well.