LVM and VxVM

dd copy of disks causes LVM info to be lost

 
paul_xedos
Frequent Advisor

dd copy of disks causes LVM info to be lost

Hi,

I'm copying several virtual machines ( hpvm's) onto different san hardware. The method I am using is to dd the disks which in most cases works. A few, though, kernel panic and fail to load lvm info.

 

Exact command for copying is below

 

dd if=/dev/rdsk/c2t0d0  of=/dev/rdsk/c11t0d0 bs=8192k  ( various block sizes from 4096 upwards tried)

 

Source disk

disk      7  0/4/1/0.1.64.0.0.0.5     sdisk      CLAIMED     DEVICE       HP      HSV200
                            /dev/dsk/c4t0d5     /dev/dsk/c4t0d5s2   /dev/rdsk/c4t0d5    /dev/rdsk/c4t0d5s2
                            /dev/dsk/c4t0d5s1   /dev/dsk/c4t0d5s3   /dev/rdsk/c4t0d5s1  /dev/rdsk/c4t0d5s3

Destination Disk

disk     10  0/4/2/0.55.24.255.0.0.0  sdisk      CLAIMED     DEVICE       IBM     2145
                            /dev/dsk/c11t0d0     /dev/dsk/c11t0d0s2   /dev/rdsk/c11t0d0    /dev/rdsk/c11t0d0s2
                            /dev/dsk/c11t0d0s1   /dev/dsk/c11t0d0s3   /dev/rdsk/c11t0d0s1  /dev/rdsk/c11t0d0s3

 

What I am finding is that on boot the system panics as no lvm info is found on the disk

 

WARNING: Open failed on device 0x1f000002 (error 0x5).
WARNING: Can not read LVM BOOT information (lvmrec).
WARNING: Open failed on device 0x1f000002 (error 0x5).
WARNING: Can not read LVM BOOT information (lvmrec).
WARNING: Open failed on device 0x1f000002 (error 0x5).
WARNING: Can not read LVM BOOT information (BDRA).
WARNING: SWAP device 0xfffffffe is a non-LVM partition, disallowed on LVM disk.
WARNING: SWAP device 0xfffffffe has been deconfigured (set to 0xffffffff).
WARNING: Logical volume for Dump expected but not found.
    Swap device table:  (start & size given in 512-byte blocks)
WARNING: no swap device configured, so dump cannot be defaulted to primary swap.
WARNING: No dump devices are configured.  Dump is disabled.

 

After a recovery boot of the hpvm a subsequent vgscan confirms no LVM info is present

 

# vgscan    
Creating "/etc/lvmtab".
Physical Volume "/dev/dsk/c0t0d0" contains no LVM information

 

Any ideas what could be the issue?

 

Regards

Paul

3 REPLIES 3
Artur-M
Occasional Advisor

Re: dd copy of disks causes LVM info to be lost


[...]

 Exact command for copying is below

 

dd if=/dev/rdsk/c2t0d0  of=/dev/rdsk/c11t0d0 bs=8192k  ( various block sizes from 4096 upwards tried)

 

Source disk

disk      7  0/4/1/0.1.64.0.0.0.5     sdisk      CLAIMED     DEVICE       HP      HSV200
                            /dev/dsk/c4t0d5     /dev/dsk/c4t0d5s2   /dev/rdsk/c4t0d5    /dev/rdsk/c4t0d5s2
                            /dev/dsk/c4t0d5s1   /dev/dsk/c4t0d5s3   /dev/rdsk/c4t0d5s1  /dev/rdsk/c4t0d5s3

Destination Disk

disk     10  0/4/2/0.55.24.255.0.0.0  sdisk      CLAIMED     DEVICE       IBM     2145
                            /dev/dsk/c11t0d0     /dev/dsk/c11t0d0s2   /dev/rdsk/c11t0d0    /dev/rdsk/c11t0d0s2
                            /dev/dsk/c11t0d0s1   /dev/dsk/c11t0d0s3   /dev/rdsk/c11t0d0s1  /dev/rdsk/c11t0d0s3

[...]

Hello.

is it the same disk? (c2t0d0=?c4t0d5)

 

Torsten.
Acclaimed Contributor

Re: dd copy of disks causes LVM info to be lost

If you copy the disks like this you should try to boot into LVM maintenance mode and re-write the lvlnboot information.


Hope this helps!
Regards
Torsten.

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paul_xedos
Frequent Advisor

Re: dd copy of disks causes LVM info to be lost

Hi,

 

Thanks for your help

 

We ended up using drd to clone the disks which copied the partition data and the lvm contents. For hpvms we still needed to recovery boot off iso and then import the disk group ( vg00) followed by lvlnboot -R  to make it bootable. All seems to be working now

 

Regards

Paul