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Tutor

Dec 20, 2020

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Reallocation warning message

Hello experts require some expert advice. two days ago after a disk test i got an email from my readynas 314 that disk 1 had to be reallocated and it later added this could mean a disk is failing...

StephenB
Dec 21, 2020
aniraghome wrote:

today i downloaded raidar 6.5 and it gave a number 1688 reallocation errors on disk 1? is it time to replace a new disk then?

Definitely it is time to replace it.

Opinions on when to replace a disk vary. Personally I will replace a disk before the reallocated sectors count reaches 50 myself. But everyone would say that ~1700 reallocated sectors is a failed disk.

aniraghome wrote:

i got this readynas 6 years ago in 2014 and i had then bought 4 X 3 TB Seagate Barracuda SATA III 7200rpm.

Don't get a new Barracuda - several of those are now SMR drives, and aren't good options for RAID arrays.

If you want to stick with 7200 RPM, then I'd suggest a WD Red Pro or a Seagate Ironwolf Pro. Currently shipping models start at 4 TB, so you would need to go with a bigger size. Note you'll need to upgrade two drives to the larger size to get more space in the volume. The capacity rule is "sum the disks and subtract the smallest).

Other enterprise-class SATA drives would also work (WD Gold to give one example).

rn_enthusiast

Virtuoso

Dec 21, 2020

Hi aniraghome

This disk is definitely bad! The ReadyNAS have a detection system to ensure a disk is indeed bad before alerting you. You can read more about that here in this link

So, the NAS is already doing the checks for you - i.e. are the errors increasing, etc. If it exceeds the thresholds as described in the above link, you get an alert. At that point it is time to replace the disk.

As for buying a new disk, here is a link to the HDD compatibility list

Please do ensure that you have an up-to-date backup. When disks are getting older, they will be more prone to failure. Replacing the bad disk with a new one will kick in re-sync of the RAID and this is a "strenuous" task for the disks. It is not uncommon to see disks with a long life span, fail during a resync because they were close the end anyway. A disk failure during the sync of your RAID 5, will result in RAID failure and total data loss.

So, please backup beforehand :)

Cheers

aniraghome
Tutor
Dec 21, 2020
Thank you this was informative especially the link with the reallocated sectors. I do a weekly backup and did a round of leftovers and backed them now. Fingers crossed after the new raid syncing.