Visit Our UNIX and Linux User Community


Software RAID doubt

 
Thread Tools Search this Thread
Operating Systems Linux Red Hat Software RAID doubt
# 1  
Old 07-31-2009
Software RAID doubt

hi friends,
I am having issues with adding a spare device to a failed array.

I have created RAID 1 with 3 partitions using mdadm command. Later I added a spare with
Code:
mdadm --add /dev/md0 /dev/sdb6

This works fine and when I check this with mdadm --detail command it just sits there as a spare device.
And now, if I set one of the active raid device in the array as faulty, the spare device becomes active and the failed device becomes faulty spare. This looks perfect, but once i reboot the machine and type mdadm --detail /dev/md0, both the failed device as well as the spare device are not seen in the array..

Why is this happening...where am i going wrong..?

pls help
# 2  
Old 07-31-2009
what does your mdadm.conf file look like?

what about /proc/mdstat?
# 3  
Old 07-31-2009
hi mark, i dont have an mdadm.conf file...(This is RHEL 5 system). I could not locate where this file is...sorry.
# 4  
Old 08-01-2009
What is the ouput from mdadm --detail?

You should have an /etc/mdadm.conf configuration file. If you do not have one, you need to create one.
# 5  
Old 08-02-2009
Initial stage of the raid array:
Code:
mdadm --detail /dev/md0

Code:
    Number   Major   Minor   RaidDevice State
       0       3       11        0      active sync   /dev/hda11
       1       3       12        1      active sync   /dev/hda12
       2       3       13        2      active sync   /dev/hda13

       3      3        14       -       spare   /dev/hda14

after the mdadm --fail /dev/hda13
Code:
    Number   Major   Minor   RaidDevice State
       0       3       11        0      active sync   /dev/hda11
       1       3       12        1      active sync   /dev/hda12
       2       3       14       2      active sync   /dev/hda14

      3      3        13      -       faulty spare     /dev/hda13

after rebooting..
both the faulty spare (/dev/hda13) and the newly active raid device (/dev/hda14) are removed from the array... and only /dev/hda11 and /dev/hda12 are active.
I touched a file named /etc/mdadm.conf, but nothing is configured there nor any output from that file..
# 6  
Old 08-03-2009
do this:

mdadm --examine --scan > /etc/mdadm.conf

---------- Post updated at 12:58 AM ---------- Previous update was at 12:56 AM ----------

[QUOTE=
I touched a file named /etc/mdadm.conf, but nothing is configured there nor any output from that file..[/QUOTE]

It is a conf file, not a log, so you won't get output. This is probably why you are having your issues. I have given the command on how to create this file.
# 7  
Old 08-04-2009
hi mark,
thanks. I will do as u guided and let u know the results.bye.

---------- Post updated 08-04-09 at 10:19 PM ---------- Previous update was 08-03-09 at 11:08 PM ----------

mark, I have tried as you mentioned, but i am not successful. The same things happen after I set one of the active device as faulty, (both the faulty device as well as the spare device gets removed...).

Previous Thread | Next Thread
Test Your Knowledge in Computers #5
Difficulty: Easy
The UNIX trademark is a "certification mark".
True or False?

9 More Discussions You Might Find Interesting

1. Solaris

Software RAID on top of Hardware RAID

Server Model: T5120 with 146G x4 disks. OS: Solaris 10 - installed on c1t0d0. Plan to use software raid (veritas volume mgr) on c1t2d0 disk. After format and label the disk, still not able to detect using vxdiskadm. Question: Should I remove the hardware raid on c1t2d0 first? My... (4 Replies)
Discussion started by: KhawHL
4 Replies

2. Red Hat

Software RAID configuration

We have configured software based RAID5 with LVM on our RHEL5 servers. Please let us know if its good to configure software RAID on live environment servers. What can be the disadvantages of software RAID against hardware RAID (4 Replies)
Discussion started by: mitchnelson
4 Replies

3. UNIX for Dummies Questions & Answers

RAID software vs hardware RAID

Hi Can someone tell me what are the differences between software and hardware raid ? thx for help. (2 Replies)
Discussion started by: presul
2 Replies

4. Filesystems, Disks and Memory

Software RAID

Hello, My company has inherited a Centos based machine that has 7 hard drives and a software based raid system. Supposedly one of the drives has failed. I need to replace the hardrive. How can I about telling which hard drive needs replacing? I have looked in the logs and there clearly is a... (5 Replies)
Discussion started by: mojoman
5 Replies

5. Solaris

doubt on RAID

What is the maximum size of RAID-5 volume that can be created using five, 20GB disks. ? explain me in detail. thanks (1 Reply)
Discussion started by: rogerben
1 Replies

6. Linux

Software RAID on Linux

Hey, I have worked with Linux for some time, but have not gotten into the specifics of hard drive tuning or software RAID. This is about to change. I have a Dell PowerEdge T105 at home and I am purchasing the following: 1GBx4 DDR2 ECC PC6400 RAM Rosewill RSV-5 E-Sata 5 bay disk enclosure... (6 Replies)
Discussion started by: mark54g
6 Replies

7. HP-UX

Software RAID (0+1)

Hi! A couple of months ago a disk failed in our JBOD cabinett and I have finally got a new disk to replace it with. It was a RAID 0 so we have to create and configure the whole thing again. First we thought of RAID 1+0 but it seems you can't do this with LVM. If you read my last thread, you can... (0 Replies)
Discussion started by: hoff
0 Replies

8. UNIX for Advanced & Expert Users

Software RAID ...

Hi all, I m just trying using software RAID in RHEL 4, without problem , then i wanna simulate if disk 1 is fail (thereis an bootloader), i plug off my 1st disk. My problems is the second disk cannot boot? just stuck in grub, the computer is hang. Sorry for poor concept in RAID? I use a RAID 1.... (0 Replies)
Discussion started by: blesets
0 Replies

9. SuSE

Raid software besides Veritass

Hello Lunix people, I am looking for Raid software or solution besides Veritas. Veritas has some great software but are way too costly. Does anyone know of good raid software that but NOT Veritas. I need the funcations but not the cost. (7 Replies)
Discussion started by: xtmeisel
7 Replies

Featured Tech Videos