activate raid456 module on Pogoplug (POGO-B04)

[Ichabod]

Hey there,

I want to setup a raid 5 on my pogoplug. mdadm works perfectly... as long as I use raid0 or raid1. Raid5 fails... it seems like the kernelmodule doesn't exist.

So... How can I enable this? Do I have do recompile the kernel? Despite I'm Linux experienced I'm new to Archlinux and I have no idea how to do that...

Can somebody help me?

[Ichabod]

anybody?

[Ichabod]

So... when setting up a raid 5, I always get

$this->bbcode_second_pass_code('', '[root@Pogo /]# mdadm --create --level=5 --raid-devices=4 /dev/md0 /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1
mdadm: /dev/sdb1 appears to be part of a raid array:
level=raid5 devices=4 ctime=Sun Dec 23 07:17:58 2012
mdadm: /dev/sdc1 appears to be part of a raid array:
level=raid5 devices=4 ctime=Sun Dec 23 07:17:58 2012
mdadm: /dev/sdd1 appears to be part of a raid array:
level=raid5 devices=4 ctime=Sun Dec 23 07:17:58 2012
mdadm: /dev/sde1 appears to be part of a raid array:
level=raid5 devices=4 ctime=Sun Dec 23 07:17:58 2012
Continue creating array? y
mdadm: Defaulting to version 1.2 metadata
mdadm: RUN_ARRAY failed: Invalid argument
[root@Pogo /]#
')

Google told me, that this usually is because the kernel doesn't support raid5. What do you think and how can it be solved?

[lnxbil]

Currently, there is no module for raid5 in the used kernel. You have to compile a kernel yourself or wait until someone provides a module for raid5.

[shv]

You could try if the following raid modules are working:

Download

[Ichabod]

How can I activate these Modules?

[shv]

Just put them in the right folder where the raid0/1 modules reside. Try the commands depmod -a and afterwards modprobe for the modules.

[Ichabod]

Hmm.. there aren't any .ko files. There are just some zipped .ko.gz files in the modules folder.... Someone told me, that the modules are linked statically into the kernel. Where are these modules from? How can I use them nevertheless?

[shv]

If you need zipped ko-files you can zip the *.ko files provided from the DL link. Just execute gzip raid456.ko. I compiled the kernel myself based on the configuration of WarheadSE. Just the missing raid modules were added in the configuration. You need raid funktionality statically linked into the kernel if you want to boot from the raid drive. Therefore you need a separate boot drive to use loadable modules.

The ritght path for the modules is /lib/modules/2.6.31.6_SMP_820/kernel/drivers/md. I just tried to load the raid10 module after depmod -a with the modprobe command. Afterwards I checked mdstat. The output is as follows:

$this->bbcode_second_pass_code('', 'depmod -a
modprobe raid10
lsmod
Module Size Used by
raid10 23616 0
md_mod 89488 1 raid10
cat /proc/mdstat
Personalities : [raid10]
unused devices: <none>')
So I think the modules are working with the kernel.

You can find some help on how to setup raid with the following link: http://www.howtoforge.com/software-raid1-grub-boot-debian-etch of http://www.dedoimedo.com/computers/linux-raid.html. It is for Debian instead for Archlinux but the commands instead of the package installer shall be the same.

[Ichabod]

Thanks a lot for that comprehensive reply. I zipped the modules, moved them to the right directory and called depmod... but modprobe fails. The message ist:

$this->bbcode_second_pass_code('', '[905805.640000] raid6: int32x1 29 MB/s
[905805.810000] raid6: int32x2 50 MB/s
[905805.980000] raid6: int32x4 57 MB/s
[905806.150000] raid6: int32x8 55 MB/s
[905806.150000] raid6: using algorithm int32x4 (57 MB/s)
[905806.170000] raid456: Unknown symbol async_xor_zero_sum
[905806.180000] raid456: Unknown symbol async_xor
[905806.180000] raid456: Unknown symbol async_memcpy
[905806.190000] raid456: Unknown symbol async_trigger_callback
[905806.200000] raid456: Unknown symbol xor_blocks
')

It seems like the kernel module is linked against some nonexisting dynamic libraries...

raid6_pq is working... btw...

edit: raid6_pq is working, but assembling a raid6 configuration doesn't.