Extending Virtual Disk and LVM online.

Jimmy_Dansbo at Dell.com Jimmy_Dansbo at Dell.com
Thu Jun 26 08:43:34 CDT 2008


I think that partprobe could help you in getting fdisk to see the new

/ Jimmy

-----Original Message-----
From: linux-poweredge-bounces at dell.com
[mailto:linux-poweredge-bounces at dell.com] On Behalf Of Ray Van Dolson
Sent: 26. juni 2008 15:32
To: linux-poweredge-Lists
Subject: Extending Virtual Disk and LVM online.

Hi all, got a PE2850 with a PERC 4e/Di.  We had three 174GB disks in
the system configured in a single RAID5 virtual disk (/dev/sda to the
OS).  I added three more of these disks and wanted to extend the
existing Virtual Disk.

I should note this system is running RHEL ES 4.6...

It was simple to do this via the "Reconfigure" Virtual Disk Wizard.
Everything seemed to work fine after a long rebuild process and I now
see the following:

# omreport storage vdisk
List of Virtual Disks in the System

Controller PERC 4e/Di (Embedded)
ID                  : 0
Status              : Ok
Name                : Virtual Disk 0
State               : Ready
Progress            : Not Applicable
Layout              : RAID-5
Size                : 683.11 GB (733478912000 bytes)
Device Name         : /dev/sda
Type                : SCSI
Read Policy         : Adaptive Read Ahead
Write Policy        : Write Back
Cache Policy        : Direct I/O
Stripe Element Size : 64 KB
Disk Cache Policy   : 

The size looks correct.  I do notice this...

# omreport storage controller
 Controller  PERC 4e/Di (Embedded)

ID                                : 0
Status                            : Non-Critical
Name                              : PERC 4e/Di
Slot ID                           : Embedded
State                             : Degraded
Firmware Version                  : 521S
Minimum Required Firmware Version : 522D
Driver Version                    : Not Applicable
Minimum Required Driver Version   : Not Applicable
Number of Connectors              : 2
Rebuild Rate                      : 30%
BGI Rate                          : Not Applicable
Check Consistency Rate            : Not Applicable
Reconstruct Rate                  : Not Applicable
Alarm State                       : Not Applicable
Cluster Mode                      : Not Applicable
SCSI Initiator ID                 : 7
Cache Memory Size                 : 256 MB
Patrol Read Mode                  : Auto
Patrol Read State                 : Active
Patrol Read Rate                  : Not Applicable
Patrol Read Iterations            : 4722

Not sure why the state is "Degraded" -- all of the physical disks
appear to be fine.

In any case, fdisk still shows that /dev/sda is the original 293.3GB.
Hmm, probably need to rescan the SCSI bus?

# echo 1 > /sys/bus/scsi/drivers/sd/0\:2\:0\:0/rescan
# echo 1 > /sys/bus/scsi/drivers/sd/0:2:0:0/block/device/rescan
# dmesg
SCSI device sda: 1432576000 512-byte hdwr sectors (733479 MB)
sda: asking for cache data failed
sda: assuming drive cache: write through
SCSI device sda: 1432576000 512-byte hdwr sectors (733479 MB)
sda: asking for cache data failed
sda: assuming drive cache: write through

So it seems like the OS has detected the new array size, but fdisk
still does not:

# fdisk -l /dev/sda

Disk /dev/sda: 293.3 GB, 293391564800 bytes
255 heads, 63 sectors/track, 35669 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1          13      104391   83  Linux
/dev/sda2              14       12761   102398310   8e  Linux LVM
/dev/sda3           12762       25509   102398310   8e  Linux LVM
/dev/sda4           25510       35669    81610200    5  Extended
/dev/sda5           25510       27421    15358108+  83  Linux
/dev/sda6           27422       27943     4192933+  82  Linux swap
/dev/sda7           27944       35669    62059063+  83  Linux

Is there something I am missing?  Maybe I just need to reboot. :(

Oh, and for posterity's sake, here's /proc/scsi/scsi:

# cat /proc/scsi/scsi 
Attached devices:
Host: scsi0 Channel: 00 Id: 06 Lun: 00
  Vendor: PE/PV    Model: 1x6 SCSI BP      Rev: 1.0 
  Type:   Processor                        ANSI SCSI revision: 02
Host: scsi0 Channel: 02 Id: 00 Lun: 00
  Vendor: MegaRAID Model: LD 0 RAID5  279G Rev: 521S
  Type:   Direct-Access                    ANSI SCSI revision: 02


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