[linux-lvm] "lvconvert --mirrors 1 --stripes 3 vgtest/lvtest" command succeeds, but no stripes

[Gang He]

Hello Guys,

I found lvconvert command (in lvm lvm2-2.02.120) did not handle "--stripes" option correctly.
The reproduce steps are as below,
# vgcreate vgtest /dev/vdb /dev/vdc /dev/vdd /dev/vde /dev/vdf /dev/vdg
# lvcreate -n lvtest -L 8G vgtest
# lvconvert --mirrors 1 --stripes 3 vgtest/lvtest
# lvs -o+stripes
  LV     VG     Attr       LSize Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert #Str
  lvtest vgtest rwi-a-r--- 8.00g                                    12.21               2

But if you create LV using lvcreate command directly, the command succeeds with stripes.
e.g.
# lvcreate --mirrors 1 --stripes 3 -L 4G vgtest
# lvs -o+stripes
  LV     VG     Attr       LSize Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert #Str
  lvol0  vgtest rwi-a-r--- 4.01g                                    8.67                6

I also use lvm2-2.02.180 to reproduce this issue, the lvconvert command works like before,
but the command will print out a message, like that,
# lvconvert --mirrors 1 --stripes 3 vgtest/lvtest
  Command does not accept option: --stripes 3.

Why do we can not use lvconvert to do like that, design issue? but lvcreate can do that.
What limitations are there between mirrors and stripes?

Thanks
Gang