I'm using a very old ReadyNas Duo v2 which I set up as a redundant pair of disks. However, I have just noticed it is now reporting a status of "Volume C: RAID Level X2, not Redundant. A disk failure will render this volume dead.; 1023 GB (55%) of 1841 GB used"
Both disks are reported as functioning normally.
I'm not sure when or why this happened, since it stopped sending alert emails a while ago.
I can't find anything online to advise on what I can do about this or how to set it back to redundant. Can anybody help please?
"Syncing" is re-creating the RAID-1 mirroring - copying the contents of one drive onto the other. If the volume is degraded and NOT syncing, then something is really wrong - generally a failed disk (despite the status you are seeing).
The dashboard should tell you if the NAS is syncing. I'm not sure where though, as I've never owned a v2 ReadyNAS (though I do have other models).
RAIDar will also tell you (one of the disk icons will be blinking).
I suggest downloading the full log zip file from the dashboard. There is a lot of information in there (much more than the web interface shows). If you need help analyzing it, let us know.
If you do not have a backup of the files, then you should make one right away.
Both disks report as healthy on the dashboard, on RAIDar and on the device itself - no blinking lights.
I can't see anything on dashboard about sync status.
The log contains a number of historic reports of uncorrectable errors on both disks, although the most recent log is "Volume scan found and corrected errors".
So I guess I need two new disks and somewhere to dump everything in the meantime?
The log contains a number of historic reports of uncorrectable errors on both disks
So I guess I need two new disks...
Probably. One next step (after backup) is to connect the disks to a Windows PC (either with SATA or with a USB adapter/dock) and test them with vendor tools. Seatools for Seagate, WDC's dashboard software for WDC. If you do this, power down the NAS before removing a disk (and leave it powered down until the disk is reinserted).
Some disk errors can be a result of a failing power brick (not supplying enough power for the disks). Though I think uncorrectable errors are more likely to be the disks, and not the power.
Any idea how I get the NAS to start syncing again once I replace the disks?
Normally you'd hot-swap one disk (NAS running) and wait for the resync to complete before doing the second.
But in this case you end up needing to do a factory default with both new disks in place. Then you'd need to reconfigure the NAS from the web ui and restore the data from your backup. No harm in trying the hot-swap procedure first as long as you have the backup.
Ignore Netgear's hardware compatibility list for disks - it hasn't been updated for years. A lot of desktop-class drives in the 2-6 TB range are SMR and should be avoided. Good options are Seagate Ironwolf or WD Red Plus. Avoid WD Reds, as they are (regrettably) SMR. Enterprise class drives are also fine, but IMO are over-kill for entry-level NAS like the Duo v2.
