I am running Centos 6.2 and the hard disk in the system started to fail, so I was able to clone it to another, slower disk to keep things running temporarily.

I want to replace that disk with a new one, but the new one is slightly smaller than the original and the partitions don't fit. The disk has an LVM on it, and while there is plenty of unused space and I was able to resize the partitions inside the logical volume (doing a resize2fs followed by an lvreduce) so that there is free space, I cannot shrink the LVM itself to get the physical partition to be small enough so that I can clone it to the new disk.

I have tried to vgreduce it (while booted into a rescue cd) but I am told it is "still in use". I also looked at pvresize but that gave me an error (sorry, did not make a note) and would not do anything.

I also tried gparted to resize the partitions as I cloned the disk, but found that it does not support lvm2.

Is there a way to get there from here?

Thanks,

Barry

Actually, you may be able to do it more simply using dump and restore. (assuming the same filesytem type in use...) As long as the old filesystem is smaller than the new partition, the restore command will do the right thing.

Create fresh and clean filesystems and mount them on your OS.
install dump and restore.

resize your old disk to slightly smaller than the new replacement disk's.

note the disk partitions that correspond to your old disk

cd <new mount point!)
dump -0af - /dev/<partition on old disk> | restore -rf -

run fsck on the restored filesystem, if all is well, delete the "restoresymtable" file.

--jason

The part about "resize your old disk to slightly smaller than the new replacement disk's." is exactly the part I can't figure out how to do. So if you could tell me how I can do that, then I am all set.

Hi,

Sorry, I made the assumption you had already done that based on a tiny blurb in your initial post.

once you use resize2fs, you don't really need to do much else, at least as far as using the dump command is concerned. Resize2fs will alter the size of the filesystem, but not the partition size. dump looks only at the filesystem-block level, and the partition size won't even interest the program. That's why I suggested dump: you can totally skip resizing the original partition.

Actually, now that I think about it, so long as the actual used filesystem space is smaller than the destination partition, dump and restore are smart enough to do that correctly.

restore will take the output of dump (or a dump file) and re-build the filesystem structure onto an existing filesystem. It CAN be used to restore to a subdirectory on a used filesystem, it is best to have a clean filesystem to restore to.

dump and restore will ALSO place important files such as your boot images (if it's THAT partition) at the correct inode number, which rsync, tar, cp, et al will not. dump and restore also correctly handle sparse files, sockets, block and character devices, and will stay in it's own filesystem (won't accidentally backup up /proc for instance).

so I will carefully list out the steps:
once done, mount the new filesystem and make sure it looks right. alter your fstab and boot into it.

--jason

I ended up following the directions here: http://fedorasolved.org/Members/zcat...-new-partition to shrink the physical partition enough so that I could clone the disk to the new one using Acronis True Image. Things seem to working ok with the new disk, and hopefully will stay that way.

Good! I am glad it worked for you! No doubt, there is always more than one way to do it.

--jason