I have a ReadyNas 104 with 2 WDC WD40EFRX-68WT0N0 4TB NAS HDs.
Out of the blue, the system started to show the 2nd HD as DEGRADED.
I have destroyed, reseted the hole system and formatted both HDs. If I leave just the first one running it seems to be ok. If I plug the second one, it says that the volume is degraded, and if I run a test it shows that disc failed in the test, but without saying WHY it failed.
There is any kind of error or warnings other than "volume degraded". If I plug the HD in another CPU, I can format and use the HD without any warnings or errors.
No matter what I do, the system show that this volume is degraded.
That's what I'm thinking, replacing the disc! I've already disconnected it.
Is it possible to downgrade the RAID 1 to JBOD so the unit stop flashing "DEGRADED" all over while I can't afford a new disc? (I'm brazillian, it's very expensive to buy a new HD now... I will have to wait a few months until I can get a new one.
Is it possible to downgrade the RAID 1 to JBOD so the unit stop flashing "DEGRADED" all over while I can't afford a new disc?
If you are using the web ui, that would require destroying the volume and creating a new one. You'd need to reinstall any apps, recreate the shares, backup jobs, and similar stuff. And restore all the data from a backup.
There is a way to do it with the linux command line (ssh), but I don't recommend going that route unless you already are comfortable with linux. Also, it's best to make sure you have an up-to-date backup if you go that route.
FWIW, you should make sure you have your important data backed up anyway, as it is quite possible that disk 1 will fail while you are waiting.
I'm quite comfortable with linux / unix. If you have a how-to, I would like to try.
Enable ssh (if not enabled already). Then log in as root, using the the NAS admin password.
The process of removing the failed drive from the array is actually pretty simple (it's much more complicated if you are removing a drive from RAID-5 or other more complicated modes). It's described in the second post here:
If you vertically expanded the volume in the past, you will have multiple RAID groups (not just md127). If that's the case, you'd need to repead his process for the other RAID groups in the volume. You might also need to do it for the OS partition (md0).
A single-drive JBOD on ReadyNAS is actually nothing more than a RAID1 with a missing disk that just doesn't report that it's missing. So unless the warnings bother you, there is no reason to change anything. But if you really want to, see this: Reducing-RAID-size-removing-drives-WITHOUT-DATA-LOSS-is-possible.
