All the data is distributed in strips across every drive without any redundancy (i.e., parity) or mirroring, therefore if you lose a single drive, each file will have a corresponding proportionally sized piece missing from that file. Therefore, when someone says they can "rebuild" your array from parity... Don't believe them. There is no parity.
There are also no reserves in a stripe; hence, when you want to recover from a failure you have to go back to every disk (including the dead one) and reassemble the data from what was able to be read. How much recovered information you get depends entirely upon how much of the damaged area could be read.
This is the reason why RAID 0 runs so fast and why a loss of even one drive impacts all files equally. Not just a part of those files.
The RAID 0 divides data into blocks called stripes, usually 64 KB or 128 KB long, and distributes these blocks across the drives in a rotating pattern: block 1 goes onto drive 1, block 2 goes onto drive 2, etc. When either writing to or reading from an array using RAID 0, both operations occur simultaneously across all disks. This is where the speed comes from.
In summary, since every file has to go on each disk it creates a situation where no one file will ever reside completely on one individual disk. An example would be a 1 MB document created on a four-disk striped RAID array that was striped into eight 128KB portions. If one of those disks fails, then one fourth of that entire document is also gone. And the same thing happens to all other documents as well. A quarter of each of them is gone too.
This is the reason why losing one disk in a RAID 0 configuration makes it appear like you've lost all your data. This is because RAID 0 arrays do not just lose data — they lose their ability to maintain "coherence" of information.
So, if you want to recover a RAID 0 after losing one disk, the only route is to make the lost disk usable again.
There are several types of RAID configurations including RAID 5 and RAID 6 that keep track of parity for the failed member so it can be calculated back. RAID 0, however, does not add anything additional onto its members — there is absolutely no redundancy within the group.
This is where the real work happens. This involves replacing donor heads, repairing the boards, doing firmware repair to make the physical disk usable. Once this process has been completed, each member in the set will begin normal imaging.
Files that are small enough to be stored within one stripe of an existing disk can be recovered whole. Files that are larger than one stripe typically do not recover well.
When severe damage occurs to a disk, such as platter scoring, or when a controller becomes unusable it results in a portion of every file being lost. There is no procedure available to recover that missing share.
The exact same processes as with any array but with much less room for error.
You don't have redundant data to fall back on if you make an error. Each write is a write to the sole copy.
Knowing the stripe order will save you time during reassembly. The stripe order can also be deduced; knowing it does.
Controller options labelled recover or repair usually mean "recreate," which will overwrite the RAID's metadata describing how your data was laid out on disk(s).
Send them all — especially the non-working one; it's the entire job. Without it, a RAID group can only ever be a partial set.
The reconstruction process can be easily understood once all members have been made readable.
Each disk will be captured as a read-only image first; if a disk fails, it should be repaired before continuing with the rest. The stripe size appears as a repeating structure on each image. Each disk's position is determined through trial-and-error with different configurations until the file system structures resolve as coherent structures as opposed to random noise. The offset is confirmed in the same manner.
Next, the array is reconstructed virtually from the individual images outside the controller. The file system is then rebuilt using the reconstructed volume. RAID work in Manchester is from £500 +VAT after a free 48-hour diagnostic. A 50% deposit may be required when one or more members require physical repair.
Only by recovering that physical disk. RAID 0 does not include any parity or mirrored volumes. Therefore, there is nothing to use to calculate which missing stripes need to be recovered. You simply must get the failed member readable and capture images of all disks.
The reason for this is because striping distributes a file's contents amongst all RAID 0 disks. So if you have a document on a four-disk RAID 0 array, the document will be distributed in fragments across all four disks. If you lose one of these disks then you are going to lose a portion of every document (a quarter) as opposed to just losing a quarter of the documents themselves.
Small files that completely reside in the same stripe on one of the remaining disks may be able to be recovered. Larger files cannot, since they would be missing their portions residing on the lost disk. Therefore, even successful recoveries would be fragmented at best.
There is nothing to reconstruct — and "recovery" or "repair" options typically refer to recreate, which writes new metadata on top of the existing metadata describing how your data has been organised. Just shut down power instead.
Where speed is essential and being unable to access the data will cause some inconvenience — such as with scratch space, editing cache or other applications whose outputs are easily reproduced. This is not storage and it is not a backup — the odds of failure are higher than with a single disk, not lower.
From £500 plus VAT after a free 48-hour diagnostic. Where the failed member needs board-level work there is a 50% deposit; the balance is due only on successful completion.