On Jan 29, 2010, at 9:16 PM, Brian Mathis <brian.mathis at gmail.com> wrote: > On Fri, Jan 29, 2010 at 9:09 PM, Ian Blackwell <ian at ikel.id.au> wrote: >> On 30/01/2010 12:09 PM, Victor Padro wrote: >>> Hello, >>> >>> I was wondering if someone could help me, >> I'll try... >>> I want to use one array with the 2 500GB HDDs in RAID1 for the OS >>> and >>> for some VMs, >> That will work OK. >>> and the other 4 1TB HDDs I want to create an array in >>> RAID5 or RAID10 for file sharing across my home Network. >>> >> You can use these disks in a RAID5 array, but not RAID10. I fairly >> sure >> you need more than 4. RAID10 is mirrored, so you only have "2" >> disks in >> the array, which isn't enough for parity/striping stuff. You need at >> least "3", which would mean 6 disks for RAID10. >> >> Having said that, I'm assuming you want to use the entire hard disk >> as a >> participant in an array. You could create 2 x 500Gb partions on each >> disk and then you have 8 x 500Gb partitions to use in a RAID10 array. >> This approach sacrifices some redundancy though. If a disk dies >> entirely, then you will lose two participants in the RAID array, >> which >> may or may not be catastrophic - it depends on what you put where... >>> I found a guide but it's a little bit outdated and it's for >>> Debian... >>> >>> Do you have any other pointer I can read/use? >>> >> http://wiki.centos.org/HowTos/SoftwareRAIDonCentOS5 >> >> I've mostly installed RAID arrays at install time, which you'll >> need to >> do as well if you want to put the OS on a RAID1 array. >>> >>> TIA. >>> >> Ian > > RAID10 does not use parity, it's just a mirror of stripes, so 4 disks > will work perfectly fine with it. > > Use RAID10 for speed, and RAID5 if the space is more of an issue. > With RAID10 you lose 1/2 the total space, and with RAID5 you lose 1 > disk's worth. Small correction RAID10 is a stripe of mirrors rather then a mirror of stripes which does not provide the same resiliency. -Ross