How check progress of lvconvert --replace

Question

I'm replacing few disks configured with RAID5 at LVM.

The command used to replace is

lvconvert --replace /dev/oldpv vgname/lvname /dev/newpv

It's start the process in background.
The parameter -i # have no effect , either -v

I try a lot of options at lvs -o +<fields> (and pvs, vgs) , no one return this progress..

I want check the progress because are big disks and fews LVs. This take few minutes running , I don't want to start the next LV while the current process still running...

For now I'm monitoring the I/O using dstats/iostats command but this is very ugly way to check this...

Answer 1

I'm not 100% sure about RAID5, but for mirrors use

# dmsetup status

rootvg-testmirror: 0 9216000 raid raid1 2 AA 3233673/9216000 idle 0

In this example its about 33% when you evalute 3233673/9216000

I haven't enough disks to create a test RAID5, but I'm sure it'll be something similar.

Answer 2

Expanding on banjo67xxx's answer you can get the percent complete (with decimals) using the following:

echo "(`dmsetup status | tail -n 1 | awk '{print $8}'`)*100" | bc -l

If you want to limit the number of decimal places you use a scale declaration in the string echoed to bc. Here's the same command constrained to 2 decimal places:

echo "scale=2; (`dmsetup status | tail -n 1 | awk '{print $8}'`)*100" | bc -l