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Is RAID 0 as risky as people say it is?

Is RAID 0 as risky as people say it is?

I'm just about to set up my hard drives with RAID 0. Is it really as risky as people say it is?

Asked by: Guest | Views: 27
Total answers/comments: 4
Guest [Entry]

Yes. If you lose just one drive in the array, you lose everything. Which means anything on RAID 0 must have a backup.
Guest [Entry]

Speaking from personal experience of losing data, I'd definitely recommend you save yourself the headaches and avoid RAID 0. For each drive in the array, you increase the chances of losing all the data. I had 3 drives in RAID 0 and the middle drive broke only a few months later, losing nearly 1TB of data.
Guest [Entry]

"I dont think Raid 0 is risky at all. I personally run raid 0 for my os for benefited speed. You could hose my raid config any time of any day and I wouldn't lose a thing. I have my system set up correctly, to get the benefits of speed while having little to no possible loss of data.

The only risk is for people who don't know how to distribute risk.

I can say the above because I simply only work on important files on another drive than that being used to hold my OS. I install applications and stuff on my main OS drive, but their config files and such are all on a secondary drive. That secondary drive is then mirrors to another drive and I then make weekly backups of that mirror to a external drive. If my Raid 0(OS Drive) were to fail, I simply pull the drive/s out and put another one in. Take a Linux live cd and use a program like dd or cat to copy a already made image over onto the raid drives. I restart and now my system is back up to a pristine state."
Guest [Entry]

"RAID 0 can be a great solution in many cases where downtime is not critical.

RAID gives you speed, or redundancy or both. RAID is not a backup solution as it only guards agains hardware failure, only one type of failure that can cause data loss. So that means you need to have a backup solution in place regardless of the RAID type you use.

Regardless of the RAID type you employ you will have degraded performance in case of a disk failure or array rebuild, and since these days HDD's are getting larger and larger and speed is more or less stagnant - the rebuilt time can stretch to days or even weeks and create unnecessary stress to the disks.

I personally prefer to run RAID 0 which in case of a disk failure will be restored from backup. That to me is the faster, cheaper, less stressful solution since a bit of downtime is not really a concern.

Remember , when you are rebuilding an array , every block of data is being read / written on all disks, regardless of the quantity of useful data on the disks. In practice that usually translates on a much faster data rebuilt from backup compared to a RAID rebuild after a disk failure. Combined with significantly less write / read cycles in normal operation of RAID 0 compared with RAID 1 / 10 or RAID 5 / 6 it will translate in less disk failures overall.

All of the above is true if you have a sound automatic backup strategy in place , for example:

continuous backup on hot files
daily backups on cold(ish) files
weekly backups on all files on media that is located remotely.

To minimise downtime even when using RAID 0 you can tier the hot data backup on fast mediums like and external SSD, since the hot data-set is usually small and external SSDs are quite cheap these days, and backup cold data on slow mediums. Most commercial NAS systems, event the cheap ones, will e able to do that for you these days without much of a hassle.

In mission-critical systems all of the above is irrelevant as downtime is not really an option , but even then there are still better solutions in place - like snapshots replication on ZFS, brtfs or erasure coding or server redundancy with failover systems in place."