Topic: Adding 4th disk to RAID5? - SME7

[deznuts]

I was preparing to use raidREconf but it requires an /etc/raidtab file - which i do not have.

Current members of the RAID include hda, hdb and hdd. I would like to add hdg as a member.

Running latest SME7 - ran yum update and yum upgrade earlier today.

Code: [Select]

[root@betsy ~]# cat /proc/mdstat
Personalities : [raid1] [raid5]
md2 : active raid5 hdd2[2] hdb2[1] hda2[0]
      490014208 blocks level 5, 256k chunk, algorithm 2 [3/3] [UUU]

md1 : active raid1 hdd1[2] hdb1[1] hda1[0]
      104320 blocks [3/3] [UUU]

unused devices: <none>

Code: [Select]

[root@betsy ~]# fdisk -l

Disk /dev/hdg: 251.0 GB, 251000193024 bytes
255 heads, 63 sectors/track, 30515 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System

Disk /dev/hda: 251.0 GB, 251000193024 bytes
255 heads, 63 sectors/track, 30515 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/hda1   *           1          13      104391   fd  Linux raid autodetect
/dev/hda2              14       30515   245007315   fd  Linux raid autodetect

Disk /dev/hdb: 251.0 GB, 251000193024 bytes
255 heads, 63 sectors/track, 30515 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/hdb1   *           1          13      104391   fd  Linux raid autodetect
/dev/hdb2              14       30515   245007315   fd  Linux raid autodetect

Disk /dev/hdd: 251.0 GB, 251000193024 bytes
255 heads, 63 sectors/track, 30515 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/hdd1   *           1          13      104391   fd  Linux raid autodetect
/dev/hdd2              14       30515   245007315   fd  Linux raid autodetect

Disk /dev/md1: 106 MB, 106823680 bytes
2 heads, 4 sectors/track, 26080 cylinders
Units = cylinders of 8 * 512 = 4096 bytes

Disk /dev/md1 doesn't contain a valid partition table

Disk /dev/md2: 501.7 GB, 501774548992 bytes
2 heads, 4 sectors/track, 122503552 cylinders
Units = cylinders of 8 * 512 = 4096 bytes

Disk /dev/md2 doesn't contain a valid partition table

Code: [Select]

[root@betsy ~]# mdadm --examine /dev/hdg
/dev/hdg:
          Magic : a92b4efc
        Version : 00.90.00
           UUID : 29611f21:4d0c06b7:ace85af2:7cd37e62
  Creation Time : Sun Feb  5 21:18:05 2006
     Raid Level : raid1
    Device Size : 104320 (101.88 MiB 106.82 MB)
   Raid Devices : 3
  Total Devices : 4
Preferred Minor : 1

    Update Time : Sun Jul 16 15:39:12 2006
          State : clean
 Active Devices : 3
Working Devices : 4
 Failed Devices : 0
  Spare Devices : 1
       Checksum : d1f73abc - correct
         Events : 0.1521


      Number   Major   Minor   RaidDevice State
this     3      34        0        3      spare   /dev/hdg
   0     0       3        1        0      active sync   /dev/hda1
   1     1       3       65        1      active sync   /dev/hdb1
   2     2      22       65        2      active sync   /dev/hdd1
   3     3      34        0        3      spare   /dev/hdg


Using some other forum posts I think I have successfully created the raid1 md1 100MB partition on hdg but I am not sure. It may be setup as a spare?. My major concern is growing the "/".

I guess it is unnecessary and silly to mention that I dont have this data backed up so I obviously dont want to make any mistakes.

[raem]

deznuts

> I guess it is ... silly to mention that I dont have this data backed up...

It's not silly to mention it, but it is extremely silly NOT to have it backed up, considering the inherent danger in what you are doing !

[deznuts]

I have the important data backed up I just dont have a way to backup a full 500GB of data . . .

Looking at bugzilla 65 raid 5/6 admin console functionality is classified as "FUTURE" . . . . so is there anyone that can tell me how to do it from the shell now?

I am sure there are other admins of raid5/6 setups out there that would love to know or share their knowledge.

the dungog guys are geniuses . . .maybe they can make a template?