Where in the netgear provided handbooks does it provide instructions for 2 of 4 failing drives. For example, does new replacement drive need to be formatted. Can 2 drives be replaced at same time. Will I lose data from remaining 2 drives during this process. Does server need to be in boot mode, etc. Ordinarily, disks can be of different sizes - is this true for replacement disks as well?
Do you have a backup? If your data is important to you then you shouldn't store it on just the one device. Multiple disk failures are an example of a problem that you can run into that can lead to needing to restore from backup. See Preventing Catastrophic Data Loss
The replacement disk should have no partiitons on it. Generally you should be able to just insert a brand new disk, but you can hook the disk up to your PC and delete any partitions off the disk if you want.
One disk can be replaced at a time. When the disk is replaced there will be a resync which will put heavy stress on all your disks. If there is a second disk failing then the resync may finish it off leading to the volume going offline and potentially losing all the data.
So with 2 disks failing it would generally be advisable to backup what you can as the first step.
Can you send in your logs (see the Sending Logs link in my sig) so I can get a better understanding as to what is going on in this particular case?
Thank you for your reply. I unfortuneately had some employment issues to deal with so was unable to address until now. Because I have a data file exceeding 6TB's I really didn't have a backup option unless I purchased a business license with dropbox/chrome to exceed the size of the typical free offering. I see now that was poor planning and a dumb move on my part. Is there a way to estimate the size of a backup file - thinking the file would be compressed, or can I just assume it will be the same size as the orginal file?
