Today my netgear's display started flashing "data degraded". I have checked the logs and I was prompted to update firmware which I am currently doing. Now the display is reading: "recover data 0.67%". I am also attaching a screenshot of the Volumes as one of the disks is marked yellow. I have taken this to mean that it is the snapshots that are degraded but I am not sure what this means or what I need to do next. Have I lost data? What is the hard disk "recovering"? Do I need to purchase another hard disk?
I have taken this to mean that it is the snapshots that are degraded
No, this has nothing to do with snapshots. X-RAID single redundancy (or RAID-1/RAID-5) is designed to allow you to reconstruct any single disk from the remaining disks in the array. Something triggered that process. It might have been an disk error, or it might have been an unexpected shutdown (power loss).
I am also attaching a screenshot of the Volumes as one of the disks is marked yellow.
Likely that is the disk that is resyncing.
You can download the log zip file from the logs page and take a closer look. mdstat.log should give an indication on which drive is resyncing (though you might need some help in interpreting what it says). system.log, kernel.log, and/or system-journal.log might contain some clues on what triggered the resync.
Not yet. Though if another disk fails, you could. FWIW, RAID isn't enough to keep your data safe. If you don't have a backup plan in place for your NAS, then you should put one in place. Getting a USB drive and setting up one or more NAS backup jobs is one way to do that.
I have downloaded the logs but I can't make head or tail of them. Would you be able to help if I were to send you them?
By "setting up one or more NAS backup jobs" do you mean that there is a way to set this up using the same NAS hard disk or do you mean using a separate hard disk. Using a USB is impossible as I need to backup 3TB of data. I also found that this NAS wasn't very compatible with my Macbook pro so I wonder what other new hard disk you would suggest buying? Preferably one that doesn't only connect through wireless as this does but also through USB cable.
Using a USB is impossible as I need to backup 3TB of data.
Not sure why you think that, since you can get an 8 TB USB drive for about $150 USD. Prices of course will vary in other locations (VAT being one factor).
You could either connect this to the NAS, and back up automatically on schedule, or connect it to your Mac when you want to make a backup, and do it manually over the network. In the latter scenario, FreeFileSync is one free utility you could use to update the backup.
I'm not a Mac user, so I can't give much guidance on USB disks for Mac.
By "setting up one or more NAS backup jobs" do you mean that there is a way to set this up using the same NAS hard disk or do you mean using a separate hard disk.
Backups need to be made to a different device. Not much value in copying the data to the same volume, as you'd still lose it if the volume (or NAS) fails.
I have downloaded the logs but I can't make head or tail of them. Would you be able to help if I were to send you them?
I'd be willing to take a look. Send a PM using the envelope icon in the upper right of the forum page. put the log zip into cloud storage (icloud or dropbox would work), and include a download link in the PM.
OK, a lot to digest there. First, regarding your degraded data. Data is the name of your main volume, so that's what's degraded. It was degraded because you lost your redundancy when one drive was "kicked out". Are you are confusing RAID redundancy with snapshots? Now, that kick-out could have been due to some hiccup, but is more likely a sign of a failing drive or, much less likely, a failing NAS. When you rebooted for the OS upgrade (a really bad idea given the data volume was already degraded), the NAS saw the previously kicked out drive as available to restore redundancy, and started a re-sync. If the drive was dropped due to some hiccup, then all will be well when it completes. But if the drive is failing, it either won't even complete the re-sync, or this will probably happen again. @StephenB gave some pointers on trying to determine which is the case. If the drive is failing, you should consider buying a replacement now.
As for a replacement "hard drive". A NAS (networked attached storage) is not a "hard drive" (also known as DAS -- direct attached storage). You need to decide which you want, as there is no device that's both. And BTW, your NAS is on your network, so using an ethernet connection for your Mac is far faster than wireless, but still slower than USB3 of a DAS. But if the cord is the issue, then a DAS is not a solution for you.
As for 3TB being too much for a USB backup, what cave are you living in? USB drives far in excess of 3TB have been available for years. You don't need (or probably even want) the drive connected to your Mac, you want to connect it directly to the NAS, so physical size is not an issue (and one with it's own power supply is recommended). But use a drive format your Mac or a new (possibly non-Netgear) NAS can read, so that if the NAS dies, you can still read the backup.
I am not sure what the advantages of a NAS over a DAS is, but if I were to go for a DAS, do you have any recommendations for a USB back up with own power supply that would have drives readable by both Mac and a new NAS?
Pretty much anything is going to work. A Mac can read an NTFS formatted drive, as can the ReadyNAS, most other NAS, and any Windows based system. There are ways to make a Mac be able to write to NTFS as well. See: How-to-use-ntfs-drives-on-a-mac.
As for the advantages/disadvantages: Assuming it's USB3 or Thunderbolt, DAS reads and writes will be faster. But it has a cord you have to deal with, and can only be accessed by one computer at a time. If you don't want it connected all the time, then you have to do so whenever you want to do your backup. And that handling is an opportunity for accidental damage. But there is no "administration" -- just plug-and-go.
A NAS is plenty fast enough for me. In fact, I don't just do backups to mine, my primary storage is on it, so I can access everything from more than one computer. It's always there on my network, and even set up for remote access and backup to a remote NAS. But when it crashes, you can loose all your data unless you have a backup, even with RAID. So if everything on it isn't already backup (meaning there is another copy on another device), then you still need backup for the items not available to restore from somewhere else. In my case, that's local NAS for most files and a remote as secondary backup for critical files.
