Re: File System conversion -- ideas

[David D. Hagood]

This is a place where logical volume management can help.

For example, suppose you have a 60G disk, 55G of data, in ext2, and you 
wish to convert to ReiserFS.

Step 1: Shrink the volume to 55G. This requires a "shrink disk" utility 
for the source file system (which exists for the major file systems in 
use today).
Step 2: Create an LVM block in the remaining 5G.
Step 3: Create a ReiserFS in the LVM block.
Step 4: Move 5G of data from the ext2 system to the ReiserFS block.
Step 5: Shrink the ext2 volume by another 5G
Step 6: Convert that 5G into an LVM block
Step 7: Add that block to the ReiserFS volume group.
Step 8: Grow the ReiserFS.
Step 9: Repeat 4-8 as needed.

This is why I'd really love to see LVM|EVM become standard, not just in 
the kernel but in the distributions - if every distro by default made 
all Linux volumes in LVM, then migrating data to bigger drives/adding 
more space/converting file systems would be so much easier.