Dne 19. 11. 25 v 18:22 matthew patton napsal(a):
Right, so LVMThin(1) conveniently omits "Oh BTW standard functionality like
pvmove() is not implemented."
lvmthin is a sub-set or sub-class of LVM, therefore any reasonable person would
assume all functionality cascades down. Because it pretty much does for
everything else.
lvm2 has 'no idea' which disk space is in-use for any individual thin LV.
(there are tools like 'thin_ls/thin_rmap' for that)
And any reasonable person would assume lvmthin would have implemented the
necessary hooks so that pvmove() would work by lvmthin handing lvm back a
linked-list of all of the pieces in the correct order so they could be written
to lvm(thick) or to another lvmthin pool. This is not that big of a cognitive
leap.
That Linux LVM thin is missing "obvious" functionality is fine, it just needs
to be stated very clearly.
Yep thanks this is a legit complain, we will improve our doc to be way more
clear about this.
I've been also thinking - that adding support of 'dumb' mirroring of thinLV
into pvmove - isn't a very difficult request - so we will see - although
obviously copying 10TiB empty thin volume isn't going to be 'a fast
operation' this way - but it's not any worse then a 'dd'.
Regards
Zdenek
