Installing Software on a RAID 1 Array

[Foshasta Jones]

I am setting up a RAID array on a PC and have some concerns.

I am trying to decided between two options. Option 1 is to have three drives in total; One drive will have the OS installed on it while the other two are in RAID 1. Option 2 is to have two drives in total in RAID 1 with the OS and other software installed on them.

If I go with option 1 will I be able to install software (games, Steam, Photoshop, Browser) on the RAID 1 array and be able to: A) use the software, B) use the software in the event that I need to replace the drive with OS installed on it; C) use the software if a drive in the RAID 1 array fails and I am forced to install a new drive and duplicate the contents of the remaining drive in the RAID 1 array onto a replacement drive?

If I do install the software on the RAID 1 array and leave the OS on a drive separate from the RAID 1 array, how will that affect performance?

If I go with option 2, if a drive does fail in the RAID 1 array (Drive #1) and I am forced to replace the failed drive with a new one (Drive #3) will there be any performance issues with the new drive in the RAID array if the remaining drive (Drive #2) from the original RAID array were to fail and I was forced to then use the newer, replacement drive (Drive #3) as a part of RAID 1 array in which both drives (Drive #3, Drive #4) are replacements for drives that have failed? In other words, what I am worried about is the performance of the operating system and other installed software suffering because it has been copied multiple times to multiple drives. Should I be concerned or is it really a non-issue.

I know I may have worded things in a confusing way. Let me know if I need to clarify anything.

 

[yoji]

I am setting up a RAID array on a PC and have some concerns.

I am trying to decided between two options. Option 1 is to have three drives in total; One drive will have the OS installed on it while the other two are in RAID 1. Option 2 is to have two drives in total in RAID 1 with the OS and other software installed on them.

If I go with option 1 will I be able to install software (games, Steam, Photoshop, Browser) on the RAID 1 array and be able to: A) use the software, B) use the software in the event that I need to replace the drive with OS installed on it; C) use the software if a drive in the RAID 1 array fails and I am forced to install a new drive and duplicate the contents of the remaining drive in the RAID 1 array onto a replacement drive?

If I do install the software on the RAID 1 array and leave the OS on a drive separate from the RAID 1 array, how will that affect performance?

If I go with option 2, if a drive does fail in the RAID 1 array (Drive #1) and I am forced to replace the failed drive with a new one (Drive #3) will there be any performance issues with the new drive in the RAID array if the remaining drive (Drive #2) from the original RAID array were to fail and I was forced to then use the newer, replacement drive (Drive #3) as a part of RAID 1 array in which both drives (Drive #3, Drive #4) are replacements for drives that have failed? In other words, what I am worried about is the performance of the operating system and other installed software suffering because it has been copied multiple times to multiple drives. Should I be concerned or is it really a non-issue.

I know I may have worded things in a confusing way. Let me know if I need to clarify anything.

Blimmy... lots of questions....

A) - yes
B) - You will lose registry and usually some components installed on C: drive... so if you lose C: the app will probably not work... would prob need do an "over th etop" reinstall and re-enter product keyes to get working again.
C) - Yes - it will work as if nothing has happened.

Well.. in RAID 1 ... any changes on one drive need be mirrored to the other... so there will be a subsequent perfromance hit.. but it most cases you would not notice it.. it will mirror in the background. If you doing massive updates, file changes on one drive.. it will take a correspondingly long time to replicate etc... so it really depends on the data use on the mirror pair.

Not entirely sure I can be bothered to untangle your mess of a question... but to cut to the chase... If a drive fails then when you put in the replacement.. .there will be a time while the raid gets rebuilt... but once rebuilt... you back to the answer in my previous paragraph. Its largely a non-issue.

HTH
Cheers

 

[Foshasta Jones]

Is there a configuration you prefer, either from the options I indicated above or something else you think may be better? I'm leaning towards a RAID 1 configuration with only two drives (no third drive with only an OS installed on it).

 

[yoji]

Well, not sure I can help much... you told us what options you considering... but not what you trying to achieve.... so its a bit difficult to give you anything definitive.

What I can say, is dont think that Raid1 means you dont have to worry about backups... Raid1 is only good for HD failure, you cant rely on it to protect you from data corruption, since data issues can be replicated between the 2 drives as part of the mirror process before you can do anything about it.

Me.. I go for speed...not because I need it.... just because I want it!!!
So I have SSD for my main OS drive
I have 2 drives in Raid0 for my data drives.
I backup weekly to network storage... which is in Raid1
and When I visit my mum I take a copy of my backup in case the house burns down.

Suits my needs, but your needs could be completely different.

Cheers

 

[egilbe]

http://en.wikipedia.org/wiki/Standard_RAID_levels

I think you want Raid 5, but not sure if your raid controller will support it.

 

[Foshasta Jones]

Best answer selected by Foshasta Jones.

 

[Foshasta Jones]

I'm somewhat familiar with the types of RAID but I wasn't sure about installing software on a RAID array; I've never tried it.

I do have a server set up that I use for backups of media, documents, etc. I was building a PC for somebody and wanted to know about the software issue. The person I'm building a PC for just wants some type of insurance again data loss and he was curious about whether or not he can install his programs on it, which I wasn't sure about.

I thought about RAID 5 but the downgrade in write performance, the potential need to purchase a controller to take some load off of the CPU and expense associated with needing to buy to 4 or 5 drives makes RAID 5 a bit out of reach.

Anyway thank you very much everybody for your input, especially you ,yoji, for untangling the mass of words that was my attempt at a question.

 

[egilbe]

Raid 5 is three drives, minimum which it looks like you already have, is why I mentioned it. Write speeds aren't that important on a array. It's the read speeds that are important.