There is one instruction on this page. All other information is descriptive. If you find a hard drive missing from your NAS unit do not replace the disk and begin a rebuild (not now).
The RAID 5 or RAID 6 system is currently in a degraded mode and since there is one drive down the data is still available. All of your files are still readable because when you access each file, the parity is being used to create the data. The NAS is operating without redundancy (safety net), however it is running. This allows us to image the entire NAS while it is in this state.
The instant you install a new hard drive and initiate a rebuild operation the controller must read every sector of every remaining disk to determine how data should be placed on the new disk. This represents the highest continuous reading activity these disks will ever endure in their lifetime.
And these disks are the same age as the one that failed. They were purchased together, sourced from the same production lot, and had been powered-on for the exact same number of hours. Disks produced in a single lot tend to fail around the same time. That’s not coincidence; it is variance within production tolerances. Therefore, a rebuild is when the second disk has the greatest likelihood of failure.
Once that happens, your degraded array becomes an array that has been partially overwritten with parity calculated from incomplete data. A portion of what has been written to the disk will be valid, while another portion will be invalid. There is nothing to track whether you’ve got the good or bad data. This is why attempting to recover after a failed rebuild is essentially a forensics exercise and will cost accordingly.
Not a restart. Off. Once a NAS unit loses access to one or more volumes, it will continue attempting recovery options. Some NAS units will provide an option to reinitialise the RAID volume to ‘repair’ the damaged unit, which writes new meta-data over existing meta-data.
Before you begin touching the disks. A good way to establish which disk was in each of your bays, and which lights indicated what.
With masking tape and a pen. The bay order is an important piece of information required to rebuild your array. If we know this piece of info, we don’t need to go through all the possibilities to find the correct answer. This will cut down on time from two weeks down to three days.
Don’t toss it. Don’t send it back under warranty. Frequently this unit is the most valuable item in the box. That’s because this unit has the “before failure” copy of the data (that has been replaced with the rebuild version) that exists nowhere else.
Truthfully. Include everything anyone did over the weekend. It is not a confession; it is a map.
Either “the volume is not active,” or the volume just disappears from the storage list. More often than not, the actual md-RAID underneath is fine; it’s either LVM or ext4 that sits on top of it that’s busted. Using QNAP’s repair tools can make things much, much worse, and that “recover volume” button doesn’t act as a recovery device in the way you’re thinking of.
SHR isn’t a standard RAID level. It is built using LVM and md-RAID stacked together, allowing disks of different size. You can’t treat it as a normal array nor read it with a regular RAID controller.
Firmware corrupted due to a power loss during an update is common, as is BTRFS volume failure on new units, which will fail in their own specific manner.
“EMmode” or an error light that flashes. Underneath is XFS, older equipment, and often a small business’s entire past.
Usually just one drive. There is no redundancy, never has been regardless of what the user thought.
It seems like one. It has redundancy, sitting quietly in the cupboard making happy sounds and contains all important information. Redundancy protects against only one disaster: a disk failing.
It doesn’t prevent you from getting hit with ransomware because it is designed to encrypt all shares it can get access to. It won’t save your data if a power spike knocks out the entire system. If you’re doing a firmware update and you end up in a situation where the volume will no longer mount after updating, there’s nothing it can do about that. And most importantly, it was never designed to be able to recover files that have been deleted in one place and then deleted everywhere at the same time.
A permanent mount of a share (backup) on the same NAS does not constitute a backup. Rather, you have created an additional version of the problem.
Get a quote from us, then drop off your drive at our Quayside reception or send it in and see if we have found anything (at no cost). The written quote will be based on the fixed bands before we start working.