NETGEAR is aware of a growing number of phone and online scams. To learn how to stay safe click here.
Forum Discussion
Pending reallocated sectors
I have a drive that is suddenly showing 61 pending reallocated sectors. Probably time for replacement, but I'm unclear as to why they should be pending. I think all forms of md will force a rewrite to a bad leg on a failed read. So I'm thinking these must have been found by the disks own background media scan. Or is there some other thing that could trigger this count and not repair them? There is a mdadm script called checkarray that is normally turned on on debian weekly to find and repair these kind of things, but I don't see it on readynas (6.2.4). Is there a reason this isn't run periodically?
It's a seagate drive out of warranty. I'm in dual redundancy with 4 4TB drives.
steve
It's a seagate drive out of warranty. I'm in dual redundancy with 4 4TB drives.
steve
4 Replies
Replies have been turned off for this discussion
- Repair bad sectors?
My understanding of pending sectors is that when they are written to then they become reallocated sectors, so lots of pending sectors is probably more of a warning sign than actual reallocated sectors.
I would assume they are detected by the disk itself.
What is the reallocated sector count? 0? - If a disk is accessed by mdraid and it gets a read error it will immediately go to the other disks to get the data and afterwards it will write that good data back to the disk with the failed read. So if a user/app reads data there shouldn't be a pending sector for very long (sub seconds). But since the disk has pending sectors I can only imagine they came from the disks own media scan (which doesn't know how to correct them using other disks). I think a disk scrub would cause them to be corrected since scrub reads everything, but there is a regular weekly job installed on debian "checkarray" which is not present on readynas. I'm just wondering why that is not enabled (the command is present in the filesystem).
My pending sector count is 61 and my reallocated sector count is 0 right now. I'm going to order a new disk. I'm just curious why netgear took out the checkarray cron job. And I'm wondering whether there is some other way to get pending sectors with reallocated sectors zero than the disk background media scan. By the way there are no md errors in my journalctl log so I don't think these errors were encountered via md which is consistent with them not being corrected.
thanks
steve dsm1212 wrote: I'm just curious why netgear took out the checkarray cron job.
The time that is run at does not suit some users. You can schedule things like disk scrubbing etc. should you wish.- Thought I posted this the other day but I guess not..
After disk scrub the smart info is totally clean. No reallocated sectors, no pending sectors, etc. Apparently on scrub the sector took the write safely. I still picked up a spare disk. I'm in dual redundancy already so I'll keep it on the shelf.
steve
NETGEAR Academy
Boost your skills with the Netgear Academy - Get trained, certified and stay ahead with the latest Netgear technology!
Join Us!
