I've got a LVM thin stripe volume across 2 drives that I'm trying to migrate to
a new larger single drive (getting rid of the old drives). Following various
information on the subject, it seems the procedure here is to first convert
from stripe to mirror, and then from mirror to linear. While attempting this, I
seem to have hit an issue on the second part of that process, and am not having
much luck resolving it.
So to start, the drives at play are sda (a new larger drive), sdb (one of the
older drives being removed), & sdc (the other drive being removed). The VG name
is "ssd".
This is what the initial layout looked like:
# lvs -o+lv_layout,stripes -a
LV VG Attr LSize Pool Origin
Data% Meta% Move Log Cpy%Sync Convert Layout #Str
[lvol0_pmspare] ssd ewi-a----- 236.00m
linear 1
thin ssd twi-aotz-- 930.59g
92.40 98.76 thin,pool 1
[thin_tdata] ssd Twi-ao---- 930.59g
striped 2
[thin_tmeta] ssd ewi-ao---- 236.00m
linear 1
(plus some other LVs which are using the thin pool volume that I've omitted)
I initiated the mirror with:
# lvconvert -m 1 ssd/thin_tdata
Replaced LV type raid1 with possible type raid5_n.
Repeat this command to convert to raid1 after an interim conversion has
finished.
Are you sure you want to convert striped LV ssd/thin_tdata to raid5_n type?
[y/n]: y
Logical volume ssd/thin_tdata successfully converted.
And this is where I'm stuck. If I follow the instructions there and repeat the
command, I get a nasty warning:
# lvconvert -m 1 ssd/thin_tdata
Using default stripesize 64.00 KiB.
Converting raid5_n LV ssd/thin_tdata to 2 stripes first.
WARNING: Removing stripes from active and open logical volume ssd/thin_tdata
will shrink it from 930.59 GiB to <465.30 GiB!
THIS MAY DESTROY (PARTS OF) YOUR DATA!
Interrupt the conversion and run "lvresize -y -l476464 ssd/thin_tdata" to
keep the current size if not done already!
If that leaves the logical volume larger than 476464 extents due to stripe
rounding,
you may want to grow the content afterwards (filesystem etc.)
WARNING: to remove freed stripes after the conversion has finished, you have
to run "lvconvert --stripes 1 ssd/thin_tdata"
Can't remove stripes without --force option.
Reshape request failed on LV ssd/thin_tdata.
If I go with other information I've found online, and skip to `-m 0` here
instead of repeating the `-m 1` command, I get:
# lvconvert -m 0 ssd/thin_tdata
Using default stripesize 64.00 KiB.
No change in RAID LV ssd/thin_tdata layout, freeing reshape space.
LV ssd/thin_tdata does not have reshape space allocated.
Reshape request failed on LV ssd/thin_tdata.
This is what the layout currently looks like:
# lvs -o+lv_layout,stripes,devices -a
LV VG Attr LSize Pool Origin
Data% Meta% Move Log Cpy%Sync Convert Layout #Str
Devices
[lvol0_pmspare] ssd ewi-a----- 236.00m
linear 1
/dev/sda(0)
thin ssd twi-aotz-- 930.59g
92.40 98.76 thin,pool 1
thin_tdata(0)
[thin_tdata] ssd rwi-aor--- 930.59g
100.00 raid,raid5 3
thin_tdata_rimage_0(0),thin_tdata_rimage_1(0),thin_tdata_rimage_2(0)
[thin_tdata_rimage_0] ssd iwi-aor--- <465.30g
linear 1
/dev/sda(118)
[thin_tdata_rimage_1] ssd iwi-aor--- <465.30g
linear 1
/dev/sdb(0)
[thin_tdata_rimage_2] ssd iwi-aor--- <465.30g
linear 1
/dev/sdc(1)
[thin_tdata_rmeta_0] ssd ewi-aor--- 4.00m
linear 1
/dev/sda(119234)
[thin_tdata_rmeta_1] ssd ewi-aor--- 4.00m
linear 1
/dev/sdb(119116)
[thin_tdata_rmeta_2] ssd ewi-aor--- 4.00m
linear 1
/dev/sdc(0)
[thin_tmeta] ssd ewi-ao---- 236.00m
linear 1
/dev/sda(59)
This is with lvm2-2.03.23-1 on Fedora 40
Any idea how I get past this point? I could just build a completely new logical
volume and manually copy the data, but there's around 40 logical volumes on
this thin pool, many of which are snapshots, so would be much easier to just
convert it if possible.
--
Patrick
