Raid 0 or Raid 5?

[Unltdone]

Okay I have a question and I'm almost certain your brains have been picked before for this very same question.

I want to setup a raid 0 array for the performance however I would like to have an internal backup should one of the drives fail. With that in mind would I then want to go with a raid 5 array with 3 hard drives or is there a way to go with 2 hard drives in raid 0 with a much larger hard drive that's not identical as a backup internal drive that will not be a part of the raid? And if it is a raid 5 setup that would be recommended is there a performance decrease in a raid 5 array?

Also how would I setup the OS in such a situation?

I apologize in advance for what must seem a very noobish question. LOL

[bchur83]

You could have a Raid 0 array and do a full backup to a larger single drive. It wouldnt really be an automatic mirror, but if you set the backup to a scheduler, then it would be done at a certain time each day/week.

[fritzman]

Okay I have a question and I'm almost certain your brains have been picked before for this very same question.

I want to setup a raid 0 array for the performance however I would like to have an internal backup should one of the drives fail. With that in mind would I then want to go with a raid 5 array with 3 hard drives or is there a way to go with 2 hard drives in raid 0 with a much larger hard drive that's not identical as a backup internal drive that will not be a part of the raid? And if it is a raid 5 setup that would be recommended is there a performance decrease in a raid 5 array?

Also how would I setup the OS in such a situation?

I apologize in advance for what must seem a very noobish question. LOL

Have a look at the last few posts in the biggest Matrix stickie... deals with exactly this scenario.

[Unltdone]

Okay now if I do raid 0 with 2 hard drives and keep a seperate hard drive to do regular backups, exactly how do I want to install the OS?

[Mr.Guvernment]

Raid is NOT a backup, but simply redundancy / uptime.

install the OS on the raid 0.

[fritzman]

Okay now if I do raid 0 with 2 hard drives and keep a seperate hard drive to do regular backups, exactly how do I want to install the OS?

Just follow the Matrix Raid with pictures stickie, only in the part where it slices off a small chunk (and I would probably still recommend you do that anyway... even if only to have the remainder as another Raid0 drive), use it all, or as I suggested, do a Raid0/Raid0 setup.

[Unltdone]

Okay but will I need to do partitioning or anything like that or when I setup the Raid 0 and install the OS?

I'm so sorry for all these questions. LOL

[fritzman]

No prob...

You need to decide 1st, whether you want to use the whole space available on the 2 x drive raid0 in a single piece or broken into two.

I would personally faviour a smaller slice 1st off just for the O/S and apps, and the rest as another raid0 for whatever you like.

However... if you follow the with pic's stickie, just use all the available space for your raid0 and then carry on from there.

Have you looked at the stickie? Might help to make sense of all this, as all these questions about how to, are dealt with in it.

Specifically http://www.ocforums.com/showthread.php?t=565177 steps 9-15, and in step 15... you'll be using all available space if you want one large 2 x drive array.

[Unltdone]

So if I understand this correctly what your saying I should do is "slice" meaning partition (I hope that's what it means) a small portion of each drive in the Raid 0 to install the OS and apps, then the rest of it I can have it run normal Raid 0 sharing.

[Mr.Guvernment]

their really would be no benefit to making 2 partitions on the raid 0, since you will have your imporant files (documents and such) on your seperate drive anyways.

[fritzman]

So if I understand this correctly what your saying I should do is "slice" meaning partition (I hope that's what it means) a small portion of each drive in the Raid 0 to install the OS and apps, then the rest of it I can have it run normal Raid 0 sharing.

Exactly...

I've never personally run a Raid0/Raid0 setup, so will fold to MrGuvernment's wisdom... I simply presumed that by using the Matrix technology and 'slicing' off a smaller part for your O/S & app's, there would be an advantage... there certainly is when the balance is in Raid1 or 5.

If you are set on doing 2 x drive matrix, then can I suggest you have a good look at the Raid0/Raid1 setup that was the subject of the last few posts in the (Main) Matrix stickie... you may find solace in having a small 'rescue' partition within the raid1 slice, so you can carry on even if the inevitable does happen and you lose your Raid0 or drop a drive.

[chuck4456]

RAID 0 sucks.
Keep in mind that if you blow a RAID 0 array then that is it.
I'd go RAID 5 and just go on with my life.
Here's a calculator in case you need it:

http://www.ibeast.com/content/tools/RaidCalc/RaidCalc.asp

[Mr.Guvernment]

Raid 0 does not suck, it just has areas it excels in better then other raid methods, but for most people it wont be used.

For me i had a 3 drive raid 0, it flew, extracting archives and copying files, flew! i loved it, then i cut down on harddrives and now have 2 x 640G WD and i dont miss the raid 0 at all.


What could be done as they say is slicing.

if you plan to use 2 x 750G drives, that is alot of space one in raid 0 which you dont need.

So, what you can do is this if you like


raid your 750 drives.

make a raid 0 partition, say 250G?
make a raid 1 partition with the rest of the space
keep your 3 drive seperate

this way you get raid 0 speed for things installed on your 0 drive, large game file loads, windows may load a little faster, opening large files will fly.

then save your important things to the raid 1 and use the 3rd drive for a 2nd backup location or just to say download random crap on.


Personally, i would do this, forget the 2 750G drives in raid 0, get 2 WD 640G drives, or Samsung F1 drives, they are darn fast on their own and use those as single drives...

what will be the main use of this computer

[goondas]

single drive
http://i39.tinypic.com/mu9aqd.png
4 drives in raid 0 (rest of space minus 60gb for system which is shown below)
http://i39.tinypic.com/23wruyo.png
4 drives in a small partition (for system for ex):
http://i39.tinypic.com/2i1mtms.png

[alinosa]

Are you going to be doing a software RAID? Or will this be implemented in hardware - a la a hardware RAID controller? I haven't looked at the "matrix" thread, but I presume it has something to do with using a region of the hard drive's platter to maintain the highest throughput?

If you are considering a software RAID solution, I think it may be wise to think about the impact this will have on other applications, since ultimately, the RAID will be a process running on your CPU just like an application. If your CPU is so gnarly that even with the extra work of handling the RAID it still is hungry then awesome. My guess is that no matter how much of a beast your CPU is, it will still bottleneck your GPU, so wouldn't advise implementing a software RAID unless this is for work instead of play.

That being said, software RAID is free where hardware RAID costs money... like in drives and a controller. Hardware RAID is the best way to go if you have the means. With a decent controller, none of the calculations are done by the CPU so the only consideration to take into account is the latency of drive I/O. With fast drives, this isn't as much of an issue, but some will swear that they can tell that there is a significant difference.

Is the RAID hardware built into your motherboard? Based on your initial comments, I'm guessing this rig is for gaming. For raw speed and some protection, I'd got with 2 fast drives in a RAID 0 and a single drive that has cyclic backups of your RAID array. There is a way to get windows to back up folders and files via the scheduler. I think you can specify whether to have a full, differential or incremental backups done to minimize the I/O on the drives' bus. This would give you max performance with a safety net of having your important stuff backed up. All done relatively cheap. If you have the means, a RAID 10 will allow you to reap the benefits of a RAID 0 setup and provide the redundancy of a RAID 1.

All those options laid out, were this to be implemented in hardware, the only worry you have for OS installation is having the appropriate driver and a means of letting windows see it during the install. I don't know how you'd be able to get the OS loaded onto a software RAID since you have to have an OS loaded to implement software RAID.

Whew!

[Whisky]

^ when windows installs, it asks for third party raid/scsi drivers so that the installation will detect the raid setup. the implementation of the raid should be done with the storage manager built into the southbridge. so there is absolutely no problem installing an os on a software raid. im speaking in terms of ICHxR though so amd folks correct me if im off :)

[SuperMiguel]

which os are u going to use? windows? or linux?

[alinosa]

^ when windows installs, it asks for third party raid/scsi drivers so that the installation will detect the raid setup. the implementation of the raid should be done with the storage manager built into the southbridge. so there is absolutely no problem installing an os on a software raid. im speaking in terms of ICHxR though so amd folks correct me if im off :)

If the RAID is set up in the south bridge, it's a hardware raid. (I'm assuming you mena in the bios, that's the only place on my motherboards that I have sene the raid setup.)

For clarity's sake:

Software RAIDs are implemented from inside the operating system- using dynamic disks if i recall correctly. This being the case, I'm almost 100% positive that you will not be able to do a software RAID then install an OS to it.

In the end, what matters is that the important data are backed up, however the problem is solved.