Raid 0 creating, lack of more devices :/

MNKyDeth · 2005-01-30 10:13:53

Well, I am fairly experienced with software raid on Linux but seem to be running into a snag. I originally set out to use mdadm on Arch. I am trying to set 2 raid 0 partitions. /dev/md/0 and /dev/md/1
The problem is with mdadm is that it seems to detect my stuff just fine but it is not allocating for the 2nd raid 0 device I want created. Basically it makes /dev/md/0 with 2 partitions of the device and it find the other 2 partitions for creating the next device but it can't since there is no /dev/md/1 in my /dev/md/ dir.

Here is the exact dmesg so you can see what I am talking about more clearly.

md: Autodetecting RAID arrays.
md: autorun ...
md: considering sdb2 ...
md: adding sdb2 ...
md: sdb1 has different UUID to sdb2
md: adding sda2 ...
md: sda1 has different UUID to sdb2
md: created md0
md: bind<sda2>
md: bind<sdb2>
md: running: <sdb2><sda2>
md0: setting max_sectors to 64, segment boundary to 16383
raid0: looking at sdb2
raid0: comparing sdb2(11727360) with sdb2(11727360)
raid0: END
raid0: ==> UNIQUE
raid0: 1 zones
raid0: looking at sda2
raid0: comparing sda2(11727360) with sdb2(11727360)
raid0: EQUAL
raid0: FINAL 1 zones
raid0: done.
raid0 : md_size is 23454720 blocks.
raid0 : conf->hash_spacing is 23454720 blocks.
raid0 : nb_zone is 1.
raid0 : Allocating 4 bytes for hash.
md: considering sdb1 ...
md: adding sdb1 ...
md: adding sda1 ...
md: md0 already running, cannot run sdb1
md: export_rdev(sda1)
md: export_rdev(sdb1)
md: ... autorun DONE.

Now, I have also tried this with raidtools instead of mdadm. Basically with the same situation this is the out put I get when trying to create the /de/md/1

mkraid -R /dev/md/1
DESTROYING the contents of /dev/md/1 in 5 seconds, Ctrl-C if unsure!
/dev/md/1: file doesn't exist!
mkraid: aborted.
(In addition to the above messages, see the syslog and /proc/mdstat as well
for potential clues.)

Now, here is the stuff in my /etc/raidtab file.
raiddev /dev/md/0
raid-level 0
nr-raid-disks 2
nr-spare-disks 0
persistent-superblock 1
chunk-size 32

device /dev/sda1
raid-disk 0
device /dev/sdb1
#raiddev /dev/md/1
raid-level 0
nr-raid-disks 2
nr-spare-disks 0
persistent-superblock 1
chunk-size 32

device /dev/sda2
raid-disk 0
device /dev/sdb2

I have checked my /dev/md/ directory to see if I have more than one device listed there but it only has the 0 and not the 1.
I just want to create more than one raid'd partition and this seems to not be working with what I have experienced in the past. An easy solution would be for someone to tell me how to add the device to /dev/md/ or how to create it so I can then load my raid. If this is supposed to get created automatically wich I am pretty sure it is supposed to be, what am I doing wrong?

Is this possibly a problem with udev ?

Any ideas and suggestions are welcome.

FUBAR · 2005-02-01 09:18:00

Before I set up my RAID-arrays, I made identical partitions on both of my discs and then set up a RAID-array for every pair of partitions.

That was with Gentoo tho. On arch, I used the same partitions and with the proper support in the kernel, my RAID-arrays are recognized. I had to set up every array once with mdadm but since then it all just works.

Are you trying to make one RAID-array, then partition it up? Or are you trying to set it up like me?

Honestly, I have no idea anymore how my RAID works. It just does.

MNKyDeth · 2005-02-01 21:53:48

I have my system already installed to my regular ide drive. I then created my partitions on my 2 drives with type fd. After I have the partitions and the partitions labled as type fd I reboot so it can pick up the new partitions with my kernel. I then proceed to put my filesystem on the partitions, like mkreiserfs /dev/md/0
But as you can see from the errros above, for some reason it isn't adding in a second raid device. It detects sda1 and sdb1 but won't add them to /dev/md/1
It is trying to put them to /dev/md/0 but sda2 and sdb2 are already labled /dev/md/0

I understand what you mean by it just works. It always has for me before. It's kind of why I am at a loss of why it won't add the 2nd raid part. I honestly do not know what is wrong but I have the raid stuff built into the kernel with *

I honestly think this is a problem with Udev somehow. When I had my partitions setup like this before I was using devfs. I then went for a period of time without my raid as I was waiting to upgrade my drives. Now, I just tried setting it back up and I cannot seem to get it. Only main diff I can tell is Udev.
For now I have reduced it to a single raid 0 device instead of 2 so I can atleast use my raid stuff.

I even went in with a Disk Edit tool and wrote 0's to the entire HDD's to make sure they were clean.

FUBAR · 2005-02-05 11:34:43

Did you run mkraid first?

Arch Linux

#1 2005-01-30 10:13:53

Raid 0 creating, lack of more devices :/

#2 2005-02-01 09:18:00

Re: Raid 0 creating, lack of more devices :/

#3 2005-02-01 21:53:48

Re: Raid 0 creating, lack of more devices :/

#4 2005-02-05 11:34:43

Re: Raid 0 creating, lack of more devices :/

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