adding another 1TB drive to raid5 array.

javaholic · 08-08-2008, 10:53 AM

so today i have encountered a problem with my what was my 3 * 1TB drive raid5 1.7TB in size. I tried to add another 1TB drive to it. I choose to use the following guide for the task:

http://scotgate.org/?p=107

but encountered a problem 17.1% some 8 or so hours in of the grow command.

now when i boot up only two of the drives show up. I'm lead to believe this is due to a stripe-size reassignment problem with the growth of a raid5 array of size greater than a few terabytes.

can anyone confirm or deny this. and is there a patch that can be applied for this?

distro of choice for this file server is debian.

obviously i want to keep the majority of the data on the three disk array as it sort of is. the increase is due to current size needing to be increased so losing it would be disasterous

thank you in advance for your time.

kenoshi · 08-08-2008, 01:29 PM

What are the contents of /proc/mdstat, as well as fdisk -l?

Also, are all 4 drives exactly the same?

Are you using raid partitions or using the luns directly?

javaholic · 08-08-2008, 01:46 PM

before i add the other two drives gives me:

Code:

md0 : inactive sda[1] sdd[2]
      1953524992 blocks super 0.91

unused devices: <none>

and fdisk -i gives me:

Code:

Disk /dev/sda: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 121601 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

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

Disk /dev/hda: 12.9 GB, 12997361664 bytes
255 heads, 63 sectors/track, 1580 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/hda1   *           1        1507    12104946   83  Linux
/dev/hda2            1508        1580      586372+   5  Extended
/dev/hda5            1508        1580      586341   82  Linux swap / Solaris
Disk /dev/sdb: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 121601 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

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

Disk /dev/hdc: 200.0 GB, 200049647616 bytes
255 heads, 63 sectors/track, 24321 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/hdc1               1       24321   195358401   83  Linux

Disk /dev/sdc: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 121601 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sdc1               1      121601   976760001   fd  Linux raid autodetect
Disk /dev/hdd: 203.9 GB, 203928109056 bytes
255 heads, 63 sectors/track, 24792 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/hdd1               1       24793   199148512+  83  Linux

Disk /dev/sdd: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 121601 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

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

javaholic · 08-08-2008, 03:16 PM

drives are all the same size.

the one drive i am adding is a different make. a samsung as opposed to 2 * identical maxtor and 1 * hitachi all 1TB in size.

javaholic · 08-12-2008, 11:51 AM

Apon reflection i think i should have mentioned that having failed step 2 in above guide i did accidently try and fail step 3 so i reckon i might have broken the superblock but am unsure how to try and rectify this. suggestions welcome. i didn't backup the data as i didn't think i would have enough space to backup to but have found a big enough space to allow me to save my stuff. how would u suggest i try and recover data even if it could in degraded mode to migrate my data. My original mdadm.conf was posted here. Thanks inadvance for ur time

javaholic · 08-26-2008, 10:59 AM

I'm pretty sure my problems were related to a faulty sata cable.

so i started raid5 array creation four days ago.

Does anybody know how long i should wait for this creation process to complete?

what is the maths for this?