asrock mobo - raid sata disks
BJB
distro on 2 sata disks connected in raid-1 mode.
I see that this mobo lets define raid arrays, but when installing linux
the array is not recognised, installation sees the 2 disks separated and
if i install on one of them, the other remains empty, no raid-1 is
performed.
Perhaps i need a linux module? A mobo bios upgrade or something else?
Tia and any help appreciated.
--
"I am your automatic lover..."
Roy Batty
Aragorn
Nearly all SATA RAID functionality available directly from the motherboard
is in fact a low-budget hardware-assisted software RAID solution.
It is best to disable the RAID features of your SATA controller in the BIOS
set-up and use the disks as plain SATA disks. You can then set up a
software RAID via the Linux RAID tools.
Most distributions support this, but bear in mind that if you want to have
the root and */boot* filesystems on a software RAID, you'll need to boot
with an /initrd/ or /initramfs/ that has the appropriate modules available
already at boot time, before the on-disk root filesystem is mounted.
If you stick to the distribution's stock kernel, you /should/ be fine - just
about every binary distribution boots their kernel with an initial ramdisk
- but should you ever decide to build your own kernel, then you'll have to
remember to create a suitable /initrd/ or /initramfs/ to go with it, or at
least, if you want your root filesystem to be RAIDed.
Hope this was helpful... ;-)
--
*Aragorn*
(registered GNU/Linux user #223157)
BJB
> BJB wrote:
Thanks a lot for your reply;
>> I have an asrock k7upgrade-600 mobo and wanted to install a debian
>> distro on 2 sata disks connected in raid-1 mode.
>> I see that this mobo lets define raid arrays, but when installing linux
>> the array is not recognised, installation sees the 2 disks separated and
>> if i install on one of them, the other remains empty, no raid-1 is
>> performed.
...
> Nearly all SATA RAID functionality available directly from the motherboard
> is in fact a low-budget hardware-assisted software RAID solution.
i just suspected that, if one thinks how much the real-hardware raid
solution cost....
> It is best to disable the RAID features of your SATA controller in the BIOS
> set-up and use the disks as plain SATA disks. You can then set up a
> software RAID via the Linux RAID tools.
> Most distributions support this, but bear in mind that if you want to have
> the root and */boot* filesystems on a software RAID, you'll need to boot
> with an /initrd/ or /initramfs/ that has the appropriate modules available
> already at boot time, before the on-disk root filesystem is mounted.
yes, i guess this is *the* problem, apart from trusting the software
solution....
> If you stick to the distribution's stock kernel, you /should/ be fine - just
> about every binary distribution boots their kernel with an initial ramdisk
> - but should you ever decide to build your own kernel, then you'll have to
> remember to create a suitable /initrd/ or /initramfs/ to go with it, or at
> least, if you want your root filesystem to be RAIDed.
now i have just one doubt at the moment: normal hardware raid-1 solution
make so that you will end up with 2 twin disks, you can disconnect one,
connect alone and it works perfectly; do the same happen with a
linux-software raid-1 solution?
Aragorn
> Aragorn wrote:
>> BJB wrote:
>
> Thanks a lot for your reply;
>
>>> I have an asrock k7upgrade-600 mobo and wanted to install a debian
>>> distro on 2 sata disks connected in raid-1 mode.
>>> I see that this mobo lets define raid arrays, but when installing linux
>>> the array is not recognised, installation sees the 2 disks separated and
>>> if i install on one of them, the other remains empty, no raid-1 is
>>> performed.
> ...
>> Nearly all SATA RAID functionality available directly from the
>> motherboard is in fact a low-budget hardware-assisted software RAID
>> solution.
>
> i just suspected that, if one thinks how much the real-hardware raid
> solution cost....
Oh, you don't have to tell *me.* :-) I've got two systems with hardware
RAID here; one with an Ultra 320 SCSI adapter and two 73 GB 10k Hitachi
disks in RAID 1, and one with an SAS adapter and four 147 GB 15k Hitachi
disks in RAID 5... ;-)
>> It is best to disable the RAID features of your SATA controller in the
>> BIOS set-up and use the disks as plain SATA disks. You can then set up a
>> software RAID via the Linux RAID tools.
>>
>> Most distributions support this, but bear in mind that if you want to
>> have the root and */boot* filesystems on a software RAID, you'll need to
>> boot with an /initrd/ or /initramfs/ that has the appropriate modules
>> available already at boot time, before the on-disk root filesystem is
>> mounted.
>
> yes, i guess this is *the* problem, apart from trusting the software
> solution....
Linux software RAID 0 and 1 are quite reliable, including the use of
hotspare disks.
>> If you stick to the distribution's stock kernel, you /should/ be fine -
>> just about every binary distribution boots their kernel with an initial
>> ramdisk - but should you ever decide to build your own kernel, then
>> you'll have to remember to create a suitable /initrd/ or /initramfs/ to
>> go with it, or at least, if you want your root filesystem to be RAIDed.
>
> now i have just one doubt at the moment: normal hardware raid-1 solution
> make so that you will end up with 2 twin disks, you can disconnect one,
> connect alone and it works perfectly; do the same happen with a
> linux-software raid-1 solution?
If you disconnect one disk from the array, the array will signal that it
runs in "degraded mode", just like with a hardware RAID. If there is a hot
spare disk, the array will rebuild itself using the hot spare. ;-)
Just read the documentation on Linux Software RAID on...
... or check out the /man/ page on /mdadm./ ;-)
BJB
...
> Linux software RAID 0 and 1 are quite reliable, including the use of
> hotspare disks.
> If you disconnect one disk from the array, the array will signal that it
> runs in "degraded mode", just like with a hardware RAID. If there is a hot
> spare disk, the array will rebuild itself using the hot spare. ;-)
>
> Just read the documentation on Linux Software RAID on...
>
> http://www.tldp.org
>
> ... or check out the /man/ page on /mdadm./ ;-)
>
Again thanks for the reply.
This line seems to be interesting to follow.
Aragorn
> Aragorn wrote:
> ...
>> Linux software RAID 0 and 1 are quite reliable, including the use of
>> hotspare disks.
> ....
>> If you disconnect one disk from the array, the array will signal that it
>> runs in "degraded mode", just like with a hardware RAID. If there is a
>> hot spare disk, the array will rebuild itself using the hot spare. ;-)
>>
>> Just read the documentation on Linux Software RAID on...
>>
>> http://www.tldp.org
>>
>> ... or check out the /man/ page on /mdadm./ ;-)
>
> Again thanks for the reply.
No problem - that's what we're here for. ;-)
> This line seems to be interesting to follow.
It might also be worth mentioning that I am running a small IRC network with
a few friends, and that our main IRC server is an AMD Phenom X4 machine
with an nForce chipset, with two SATA disks in a Linux RAID 1
configuration.
I did not install the operating system on that machine myself - CentOS 5.1 -
or set up the RAID, but apparently it was set up by my colleague with a
partitioning layout similar to what I would have done, and with all
partitions being mirrored. Just to show you that it works perfectly
well. ;-)
The only thing that was still rather experimental a while ago - although I
haven't exactly checked its progress in the meantime - is software RAID 6
support in the Linux kernel. RAID 0, 1, 5, 10 and 50 all work very well,
as does the linear approach of Logical Volume Management. ;-)
Hey, this is a Real Operating System (TM), not some braindead preliminary
alpha idea released as a production-ready business platform from that place
in Redmond. ;-)
P.S.: In the event that the /mdadm/ utility is not installed on your system
at this stage, you should get the /raidtools/ package. The RAID support
itself is already configured into most distribution kernels as loadable
modules, but you'll need the /raidtools/ package to have the system read
and properly execute the instructions in */etc/raidtab* - it's a file
similar to */etc/inittab,* but specifically pertaining to your RAID
configuration, and it's read at boot time.
Good luck! ;-)