So tell me more about RAID 1

[Ivo]

My motherboard doesn't have a hardware RAID controller, but apparently some do. So that excludes "RAIDing" the OS - although there seems to be an option of software RAIDs that I could apply to extra drives (so e.g. 1 drive with OS, 2 other identical ones software RAID 1).

If my motherboard had one, or if I buy one (I'm guessing one can buy separate hardware controllers) I could RAID before installing the OS and then everything would be mirrored.

Anything I'm missing? Recommendations? I'm pondering on getting 2 extra identical drives and software RAID them (should I go with SATA or other kind of drives?). Must check if my PSU will handle the extra load of 2 more drives.

I'm not sure if Vista Home Premium allows software RAID. Does anyone know about software RAID in Linux?

Ivo.

[puke_face]

This guide may be of some help to you.

http://en.wikipedia.org/wiki/RAID#Standard_levels

I would go with SATA drives. RAID 5 is best in my opinion, simply because of it's redundancy.

[fastbilly1]

I am about to leave work - so excuse my brevity:
- Either go the software route or buy a second hardware controller. If for some reason your raid goes to hell and your controller gets fried, and you dont have another one that is setup the same way, you are pretty fubar. I havent built a raid in several years so if they have changed that then excellent.
- Go SATAII if you can, faster the connection the better.
- Vista will support a raid array
- Why do you want to raid anyway?

[Ziggy]

I would go RAID 5 over 1 myself, but it requires another hard drive.

[Hatta]

I prefer software RAID to hardware RAID. In hardware RAID if your controller bites it, you're screwed if you can't get the exact same controller card. Software raid, you can just move your drives to a new machine.

Also, I prefer RAID 1 to RAID 5. If I have 4 drives in RAID 5 (that's 3+1 parity) and I lose 2 drives, I'm toast. If I have 4 drives in RAID 1 (that's 2 sets of 1:1 mirrors) and I lose 2, there's a 1/3 chance I'd lose half my data, and a 2/3 chance that I lose no data. RAID6 would fix this problem, but I've never had enough drives of the same size at once to put one together.

Linux makes this all pretty easy if you're handy reading man pages and howtos. It even supports booting off of RAID devices. The downside of Linux software RAID is that you can't use any of the storage from Windows if you dual boot. You're best off setting up a dedicated machine and mounting it over the network if that's the case. There are even distros designed for that purpose (e.g. openfiler).

Just keep in mind that RAID is not a substitute for a backup. If you delete the wrong file, or lose the hardware to fire or flood damage you're screwed. Important data should be backed up to a system in a different location, and kept offline until needed.

[Ivo]

I intend to continue doing backups - I had my OS drive (and only internal drive) go bad with a week old (partial) backup. I had the most important things backed, but it was still annoying to lose the time and lose the use of my desktop. Ideally I would prefer to also mirror the OS but for that I need a controller as my mobo doesn't have one.

I don't think I want to go beyond getting 2 more drives (so it would be 3 total, but I can't get identical ones to my current one now) so I'm not sure if RAID 5 is for me. I'm more interested in the redundancy part than the performance increase that comes from the striping procedures anyway.

Ivo.

[Hatta]

Ideally I would prefer to also mirror the OS but for that I need a controller as my mobo doesn't have one.

Linux software raid can boot from RAID1 devices just fine. I dunno about Windows. You also don't need identical devices, just partitions of the same size. If you had a 750gb drive and got a 1tb drive, you could partition the 2nd drive to 750+250 and use the 250 for stuff you can lose (torrents, etc).

[Niode]

If you had a 750gb drive and got a 1tb drive, you could partition the 2nd drive to 750+250 and use the 250 for stuff you can lose (torrents, etc).

If you did this you won't get the performance benefit from doing a RAID, so that's pretty much useless.

[Hatta]

How do you figure?

[Niode]

If any program were to use the 250GB partition then you would be writing to two places at once, on the same disk, therefore halfing (or worse) performance. It would be fine for storage of files that were seldom used but any kind of general use, as in a torrent stash or music drive, anytime you accessed it concurrently with software based on the primary RAID the performance would bottom out as the disk controller tries to juggle simultaneous operations on the same physical disk in two seperate locations. Not only is this taxing on the drive controller, the physical limitations of mechanical drives slows this kind of use down considerably.

You'd be better off just having the 750GB + 750GB raid and leaving the rest as unpartitioned space. If you aren't doing the RAID for performance, then you would be better off just investing in some other form of backup. In my opinion RAIDs are only worth it if you are either too lazy to backup data or you want the extra speed benefit of a striped array. The added complexity just adds to the risk of data loss.

In general partitions are always going to be detrimental to performance. Partitioning your drive for an OS partition and a Home partition is only a good idea for safety of files, if Windows decides to crap itself, as it is prone to doing everynow and then, you have less of a clean up to do afterwards.