best way to partition raid 0

ard-tullaich · 23 Jan 2010 at 23:08

Looking for some expert advice. Is it best to partition raid 0 in dos when you set up raid or do it when loading windows seven. My thoughts are the fastest performance is at the bigining of the hard drive. so i thought to partition my f3 500gb drives to 300gb and then the remainder for the second partition. Then if i understand rightly all the appplications and win 7 will be on the fastest part of the disc ie; the begining of the hard drive

droyden · 24 Jan 2010 at 00:22

Your mobo will have (presumably) on board raid, which you setup after the bios screen but before windows loads. Once you set it up you can install windows onto your new raid.

ard-tullaich · 24 Jan 2010 at 00:42

Thanks for reply -

I would like to partition the raid 0. Do I do it whilst setting up raid 0 in boot menu as I have this option, or should I partition the raid 0 drive when in the advanced menu whilst installing windows 7?
Which is the correct way?

droyden · 24 Jan 2010 at 00:52

Do it in the boot menu, doing it while installing windows will be software raid

rpstewart · 24 Jan 2010 at 11:32

droyden said:
Do it in the boot menu, doing it while installing windows will be software raid

No. You create a single array in the RAID BIOS then partition it as normal during the Windows install.

ard-tullaich · 24 Jan 2010 at 12:15

thanks all for your help. See my other threads to see if you can help me with my question about crossfire setup

ard-tullaich · 24 Jan 2010 at 13:13

rpstewart said:
No. You create a single array in the RAID BIOS then partition it as normal during the Windows install.

So when i partition during instalation of windows. My operating system will go on the beginning of the hard ie the fastest. providing i put the operating system on the first partirion i make?

rpstewart · 24 Jan 2010 at 14:03

ard-tullaich · 24 Jan 2010 at 15:32

Thank you rpstewert for your help

ard-tullaich · 24 Jan 2010 at 20:53

Just a few photos showing what i was playing with in raid in boot.

Any thoughts any body tried this with only 2 drives

rpstewart · 24 Jan 2010 at 20:56

Tried to do what? The matrix RAID stuff with a RAID1 and a RAID0 array on only 2 disks?

ard-tullaich · 24 Jan 2010 at 20:57

just trying to upload pictures

rpstewart · 24 Jan 2010 at 21:28

ard-tullaich said:
Any thoughts any body tried this with only 2 drives

Tried to do what? It's not clear what you're trying to achieve.

rz30 · 24 Jan 2010 at 21:46

rpstewart said:
Tried to do what? It's not clear what you're trying to achieve.

he has 1 drive as a stripe and the other a mirror.

ard-tullaich · 24 Jan 2010 at 22:02

when i first set a raid 0 in post . I set up raid 0 with the 2 samsung f3 500gb drives and when it asked me the size i chose 300gb .then with the remainder i set up raid 0 again using what space was left on the 2 f3's.

Kept on experimenting and with the second go i made a raid 0 300gb and made the remaining space between the 2 f3's a mirrored. just mucking about having never played with raid before. this was what i was asking at the begging. Whats the best way to partition a raid 0 .
I am going with the advised set raid 0 in post unpartitioned and then partition the raid when loading win7 in the advanced menu.

fizzy · 25 Jan 2010 at 01:22

It's generally not a good idea to mix raid types on the same drives.

In your second pic it's showing that you have your first partition striped across two disks (RAID 0) which will allow simultaneous reading and writing across the two disks - so around ("up to") twice the throughput - which is good for performance...

Then on the same two disks you have added a mirrored set (RAID 1) - which basically is slower that normal single disks since it has to write the data onto one disk, then a copy on the other. Reading will be off either disk but only at single disk speed.

So basically you are speeding things up using Raid 0, but then slowing it down again by using Raid 1 on the same disks. Also increasing the chance of the first partition failing as it's over two disks, and with no speed benefit.

What are you trying to achieve? Additional speed or resilience?

If you want both, then ideally it would be 2 disks as Raid 0 for os/games etc, and two others for Raid 1 for any important data.

Capacity is also an issue, as obviously with mirroring you loose half your disk capacity on the mirror.

If you're stuck with using two disks, and want both - depends on which is more important - speed, data security or capacity. Erm.... that's three things but you get what I mean.

weird_dave · 25 Jan 2010 at 09:46

fizzy said:
So basically you are speeding things up using Raid 0, but then slowing it down again by using Raid 1 on the same disks. Also increasing the chance of the first partition failing as it's over two disks, and with no speed benefit.

You still get the speed benefit on the first partition, the raid 1 partition doesn't slow the raid 0 on the same drives. The only slowdown you get is when both partitions are in use, but that's true of any form of partitioning.

fizzy said:
Capacity is also an issue, as obviously with mirroring you loose half your disk capacity on the mirror.

Actually, you lose all the disk capacity on the mirror

fizzy said:
If you're stuck with using two disks, and want both - depends on which is more important - speed, data security or capacity. Erm.... that's three things but you get what I mean.

Speed for me every time

I should think most people don't actually have much data that is important to back up. Being able to almost instantly recover from a HD failure on your OS drive is a huge timesaver though.

I'm now tempted to raid 0 with a big partition and a small 50GB raid 1 at the end for my important bits.

fizzy · 25 Jan 2010 at 11:26

weird_dave said:
You still get the speed benefit on the first partition, the raid 1 partition doesn't slow the raid 0 on the same drives. The only slowdown you get is when both partitions are in use, but that's true of any form of partitioning.

I was thinking this myself - but it would result in odd performance behaviour, especially since windows likes doing odd things in the background. Besides, this is software raiding rather than a nice full raid card, so no fancy dedicated hardware cache to buffer everything in mixed configurations.

weird_dave said:
Actually, you lose all the disk capacity on the mirror

Yeah ok - I was thinking of the capacity in the mirrored set.

weird_dave said:
Speed for me every time
I should think most people don't actually have much data that is important to back up. Being able to almost instantly recover from a HD failure on your OS drive is a huge timesaver though.

I'm now tempted to raid 0 with a big partition and a small 50GB raid 1 at the end for my important bits.

If you start using raid 0 on large disks, then the problem starts being partition size limitations - unless you have a 64 bit os.

Have previously tried to raid 0 2 x 1.5TB disks on XP32, and wondered why it was complaining.

weird_dave · 25 Jan 2010 at 12:16

W7 64bit, so I should be OK

I missed the bit about software raid. Would be interesting to see some benchmarks in raid 0 and mixed modes.

fizzy · 25 Jan 2010 at 12:36

weird_dave said:
W7 64bit, so I should be OK
I missed the bit about software raid. Would be interesting to see some benchmarks in raid 0 and mixed modes.

Well, most standard motherboard raid implementations are software based. The proper hardware raid cards are somewhat expensive, considerably more so that a decent motherboard...

Been using a Raid 0 setup myself for a while ( 2 x 1TB samsungs) and other than the benchmark results not really noticed that much of a difference in general use. In fact seem to suffer from disk contention mostly (multiple partitions in windows on the same raid disk) so will probably revert back to using non raid, and having windows on one, swap/temp file on another etc. May even invest in an SSD for the OS drive.