I agree with your summarisation of RAID, but I also think QNAP should offer a way to restore / reintegrate the RAID data automatically if the NAS itself fails and you need to reinitialise the disks.tgsbn wrote: ↑Sun May 10, 2020 7:13 pmI don't agree.fredrogers wrote: ↑Tue Dec 10, 2019 2:51 pmGreat insight! I wish these NAS vendors would warn people that data recovery is probably going to be impossible, before they configure their units using advanced RAID setups.philippelt wrote: ↑Tue Jan 22, 2019 3:14 am
Raid5 for home users in my opinion is just the shortest path to data disaster.
You should never count on data recovery from the salvaged disks of a defect NAS, no matter which RAID level.
The only reliable way of recovering from a NAS defect is to restore your last backup.
Data recovery from a failed RAID or from failed disks in general is always only a risky attempt to reduce the size of desaster should your backups turn out to be unusable or (shame on you) non-existent.
So the warning NAS vendors should really give is:
- Do regular backups!
- RAID is not a backup.
- RAID only protects against disk failures.
- RAID does not protect against other hardware failures.
- RAID does not protect against operating errors.
- RAID does not protect against malicious acts.
That's not to say we shouldn't try to help fellow QNAP users who for whatever reason face the need to attempt a data recovery.
- Do regular backups!
But when it comes to general warnings and recommendations, a good backup strategy that avoids the need for data recovery in the first place is much more important than adapting your RAID configuration to make data recovery easier.
I found myself in a position where the disks in my RAID-1 simple static volume had not failed, but I had to take the extensive steps listed in this thread (and more besides) to get my data back even though the data was not corrupt. All that needed to be done, in theory, was to wipe the OS partition and reinstall QTS leaving my data intact, but no such option was offered when I attempted to migrate to a new NAS.
Even if I had a backup, I would still have to go through the lengthy process of synchronizing the RAID-1 volume which writes to the entirety of the disks, as far as I can tell, causing stress on them. Then I'd also have to copy the data back to it, causing more wear on the drives.