2 RAID1 Arrays vs 1 RAID5 Array

[aosborn]

Hello.

I have a single entry level server with VMWare Server 1.x

I am adding a P400/512MB/BBWC (The Sys Drive is a RAID1 on a cheap E200, already installed and running)

I am moving 2 VMs from a slow NAS to this new card. One VM is a file server with a large QB database that's slow. The other VM is a couple GB SQL database with IIS that's also slow.

I have the option of having 2 RAID1 arrays (2 146GB SAS drives and 2 72GB SAS drives) or 1 RAID5 array (4 72GB SAS drives).

I looked online for comparison in mbps between RAID1 and RAID5 but this is different since it's hosting 2 different VMs. Do you think I'd see a large performance difference one way or another?

Thanks!

[cmacmillan]

Your options are pretty limited with only 4 drives, so - if capacity is not a factor - why not one RAID1+0 array (2x mirrors, striped)? This configuration will offer 70% of the peak bandwidth in read and nearly twice the write bandwidth versus a single RAID5 configuration. Likewise, the number of IOPS - the factor driving transactional performance - will be double.

Duncan Epping has a quick bit about RAID5 vs RAID1 in small, real world formats. This is an all things otherwise equal comparison that may answer your question more empirically. Hope it helps you form your decision.

--Collin C. MacMillan

SOLORI - Solution Oriented, LLC

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[Duncan Epping]

Do you need the amount of IOps the RAID1 or the RAID5 can produce? Raid-1 has less "overhead" than raid 5, but in Raid-5 you will have more disks so the outcome might just be roughly the same.

thanks for the link by the way... :smileyhappy:

Duncan

VMware Communities User Moderator | VCP | VCDX

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