[SOLVED] Expanded Hardware Raid 5 Array doesn't show new free space Slackware 10.2

mgallatin · 03-29-2010, 01:56 PM

Is there a way to get linux to recognize new free space on a Raid 5 array without unmounting the disk or rebooting the system?

If I unmount the file system and remount it, will it automatically recognize the new free space?

Server Specs:
Dell PowerEdge 4400
Perc 2? raid controller
Slackware 10.2

I have an old Dell PowerEdge 4400 server running a Raid 5 array. Originally it had 6 disks in this array, but it had 2 empty slots in the enclosure. So, naturally we wanted to make the array bigger. I was able to get another disk added to the system, got the raid controller to recognize it, initialize it, add it to the Raid 5 container, and then rebuild the array.

In the raid controller it recognizes the new drive as part of the array, it sees the new size and everything seems to be A OK.

Now, I know I need to extend the partition and file system to include the new free space. For the life of me I cannot figure out how to get slackware to see the new free space.

I don't think I have to reboot the system, it is not the primary file system, it is a data drive.

I'd like to do it without unmounting the existing file system, but I don't think that is possible.

PERC showing 7th disk in a Valid Raid 5 array (101 GB):

Code:

AFA0> container list
Executing: container list
Num          Total  Oth Chunk          Scsi   Partition
Label Type   Size   Ctr Size   Usage   B:ID:L Offset:Size
----- ------ ------ --- ------ ------- ------ -------------
 0    Legacy 8.47GB            Valid   0:01:0 0.00 B:8.47GB
 /dev/sda

 1    RAID-5  101GB       64KB Valid   1:00:0 64.0KB:16.8GB
 /dev/sdb             DataPart         1:01:0 64.0KB:16.8GB
                                       1:02:0 64.0KB:16.8GB
                                       1:03:0 64.0KB:16.8GB
                                       1:04:0 64.0KB:16.8GB
                                       1:05:0 64.0KB:16.8GB
                                       1:08:0 64.0KB:16.8GB

df -h output:

Code:

Filesystem            Size  Used Avail Use% Mounted on
/dev/sda1             6.4G  4.5G  1.6G  74% /
/dev/sdb1              83G   58G   21G  74% /home

fdisk -l output:

Code:

Disk /dev/sda: 9105 MB, 9105018368 bytes
255 heads, 63 sectors/track, 1106 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1         851     6835626   83  Linux
/dev/sda2             852        1106     2048287+  82  Linux swap

Disk /dev/sdb: 90.9 GB, 90994114560 bytes
255 heads, 63 sectors/track, 11062 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1               1       11062    88855483+  83  Linux

parted /dev/sdb print output:

Code:

Disk geometry for /dev/sdb: 0.000-86778.750 megabytes
Disk label type: msdos
Minor    Start       End     Type      Filesystem  Flags
1          0.031  86772.963  primary   ext3
Information: Don't forget to update /etc/fstab, if necessary.

*I am not exactly sure why fdisk sees /dev/sdb as 90.9 GB either

Let me know if you need more information.

Thanks for your help!

mgallatin · 03-29-2010, 02:05 PM

Okay, so since posting I have discovered this thread:

http://www.linuxquestions.org/questi...w-size-777639/

Which pretty much says use:
hdparm -z /dev/sdb

Is this safe while a file system is mounted?

Also, would this command be better:
partprobe /dev/sdb

I have not tried either as I read that some hdparm commands can be dangerous, and wanted to get a second opinion on the best/safest one to use.

mgallatin · 03-29-2010, 02:59 PM

Okay tried them both with the drive mounted:
partprobe didn't seem to do anything
hdparm-z had an error "BLKRRPART failed: Device or resource busy" (which is probably because there is a mounted file system)

I am going to unmount the file system on the array later today (after business hours) and try to re-run those commands. I don't actually think that partprobe is going to work as I haven't changed any partitions (there is just new unpartitioned free space).

mgallatin · 03-30-2010, 07:41 AM

So, Last night I unmounted the raid array, ran both hdparm -z and partprobe. Both seemed to run successfuly, both seemed to do nothing. Went ahead and ran e2fsck on the drive since it was unmounted.

Any ideas would be helpful, thanks again.

mgallatin · 04-14-2010, 09:01 AM

I'd thought I'd bump this thread, as its been two weeks and I have no outside feedback.

I haven't tried anything else since my last post. I am thinking of rebooting the server, although, its old and I really don't want to deal with any hassles that could arise in a reboot.

Does anybody have any advice or insight to where I should look to fix this problem. I'm not opposed to research, but my efforts have come up empty.

Or tell me I tried everything that should have worked and just do a reboot.

Just looking for a little guidance here.

Thanks

mgallatin · 05-10-2010, 11:27 AM

Just a quick followup. Rebooting the server will show the new empty space.

Unfortunately, I was unable to finish the process as the building that the server was located in flooded (completely submerged the server).

Yay for backups!

MrUmunhum · 08-21-2010, 04:48 PM

Bummer!!