SW Raid - dev mapping

ppolz · #1 7th February 2008, 12:54 PM

Hello
I need some Help please

I have a SW Raid 1 with Sata Disks. The disks maps on /dev/sdc and /dev/sdd. Yesterday another disk on /dev/sdb fails. Now the disks of the Raid changes to /dev/sdb and /dev/sdc. As result the Raid fails on startup becaus it was searching for sdc and sdd.

How can i map static to a SATA Interface, that there would be no errors on startup.

Thx
Peter

PS.: Sorry for my englisch

notageek · #2 7th February 2008, 02:25 PM

Correct me if my understanding is incorrect.

You now want to start RAID devices on /dev/sdb and /dev/sdc instead of /dev/sdc and /dev/sdd.

You may give this a try

Code:

vi /etc/mdadm.conf or /etc/mdadm/mdadm.conf 

DEVICE /dev/sdb /dev/sdc

ARRAY /dev/md0 devices=/dev/sdb,/dev/sdc

refer man mdadm and man mdadm.conf

Edit: you can also start raid device manually without the config file, try mdadm -A /dev/md0 /dev/sdb /dev/sdc

ppolz · #3 9th February 2008, 11:42 AM

I already know how to build a raid. The Problem is that i have a raid 10 of 4 drives and 4 extra drives. Sometimes i have to remove some of the extra drives for maintainance. After a reboot fedore moves the dev/sd[x] of all drives an the raid doesn't reboot because of wrong "dev's" in mdadm.conf.
Now i want do add statc devices for raid. A solution i found was to add some udev rules, but this doesn't seem to work fine for me. I think this should have to be a common Problem.

notageek · #4 9th February 2008, 04:52 PM

So I'm guessing a configuration like this in mdadm.conf does NOT work for you?

Code:

ARRAY /dev/md0 UUID=3aaa0122:29827cfa:5331ad66:ca767371

ppolz · #5 9th February 2008, 05:24 PM

I 've tried it , but without

Code:

DEVICE /dev/sdc1 /dev/sdd1

it doesn't work for me

notageek · #6 9th February 2008, 11:35 PM

How about

Code:

DEVICE /dev/sd[abcdjkl]1

or

Code:

DEVICE /dev/sd[a-z][1-9]

Globbing all possible devices.

ppolz · #7 10th February 2008, 02:58 PM

Code:

DEVICE /dev/sd[abcdjkl]1
or
DEVICE /dev/sd[abcdjkl]1

I don't know why but i doesn't work, But I solved it with some udev rules. Now i map the SATA inputs to

Code:

/dev/cont/sata1
/dev/cont/sata2
/dev/cont/sata3
/dev/cont/sata4

and added them to mdadm.conf. It seems to work fine now.

thx, Peter