[CentOS] Multiple RAID support in CentOS?
Hello, I was wondering if someone could help me, I'm putting together a Server for personal use, I want to virtualize a few servers(mail, web, ssh) and use it as a NAS, but I have a question if I can use Multiple RAID Arrays using the following HW: Intel Xeon Quad Core X3430 ASUS P7F-M LGA 1156 - LSI MegaRAID(integrated) - HighPoint RocketRAID 2640x1 2 Hitachi 500GB HDDs 4 Hitachi 1TB HDDs I want to use one array with the 2 500GB HDDs in RAID1 for the OS and for some VMs, and the other 4 1TB HDDs I want to create an array in RAID5 or RAID10 for file sharing across my home Network. I found a guide but it's a little bit outdated and it's for Debian...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? TIA. -- Linux User #452368 http://twitter.com/vpadro "Everything that irritates us about others can lead us to an understanding of ourselves" ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] Multiple RAID support in CentOS?
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 I found a guide but it's a little bit outdated and it's for Debian...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 ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] Multiple RAID support in CentOS?
On Fri, Jan 29, 2010 at 9:09 PM, Ian Blackwell 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. ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] Multiple RAID support in CentOS?
On Jan 29, 2010, at 9:16 PM, Brian Mathis wrote: > On Fri, Jan 29, 2010 at 9:09 PM, Ian Blackwell 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 ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] Multiple RAID support in CentOS?
On Fri, Jan 29, 2010 at 8:09 PM, Ian Blackwell 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 > ___ > CentOS mailing list > CentOS@centos.org > http://lists.centos.org/mailman/listinfo/centos > Thank you Ian, but I disagree in your concept of RAID10: [quote] RAID 10 RAID 1+0 (or 10) is a mirrored data set (RAID 1) which is then striped (RAID 0), hence the "1+0" name. A RAID 1+0 array requires a minimum of four drives: two mirrored drives to hold half of the striped data, plus another two mirrored for the other half of the data. In Linux MD RAID 10 is a non-nested RAID type like RAID 1, that only requires a minimum of two drives, and may give read performance on the level of RAID 0. [quote] I'll read that howto, is for fakeRAID though... TIA -- Linux User #452368 http://twitter.com/vpadro "Everything that irritates us about others can lead us to an understanding of ourselves" ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] Multiple RAID support in CentOS?
On 30/01/2010 1:42 PM, Victor Padro wrote: > I'll read that howto, is for fakeRAID though... > TIA > > Yes, I got RAID10 wrong - knew I would (haven't used it before). If you're using hardware RAID, then the Op/Sys will just see two disks and you don't really need a HowTo. How you partition/use them is up to you when you install. I know there is continuous debate about hardware vs. software RAID, but I've only ever had problems with hardware, and never any problems with software. Your mileage may vary :) Ian ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] Multiple RAID support in CentOS?
> [quote] > RAID 10 > RAID 1+0 (or 10) is a mirrored data set (RAID 1) which is then striped > (RAID 0), hence the "1+0" name. A RAID 1+0 array requires a minimum of > four drives: two mirrored drives to hold half of the striped data, > plus another two mirrored for the other half of the data. In Linux MD > RAID 10 is a non-nested RAID type like RAID 1, that only requires a > minimum of two drives, and may give read performance on the level of > RAID 0. > [quote] Please do note that md raid10 IS different from doing nested md raid1+0. The md raid10 module does other fancy stuff. ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
