On Tue, Nov 15, 2005 at 03:50:00PM +0000, Craig McLean wrote:
> Gotcha. Hopefully once the filesystem is resized down and the lvreduce
> is done, moving the physical partition boundary will not destroy any
> allocated PEs, good call on the vgcfgbackup/restore. I wouldn't know
> where to start working out the new PE count for the restore though...
> Will vgdisplay show me the new PE count after the resize?
Use "lvdisplay -m" to get a map of the segments; e.g., one of my logical
volumes shows:
--- Logical volume ---
LV Name /dev/extra/extra_disk
VG Name extra
LV UUID cTvMfD-XTIT-NQhs-vsnO-sgDq-ltXA-jVf0Pg
LV Write Access read/write
LV Status available
# open 1
LV Size 56.00 GB
Current LE 56
Segments 2
Allocation inherit
Read ahead sectors 0
Block device 253:1
--- Segments ---
Logical extent 0 to 7:
Type linear
Physical volume /dev/md7
Physical extents 130 to 137
Logical extent 8 to 55:
Type linear
Physical volume /dev/md7
Physical extents 144 to 191
This corresponds to the following metadata in the backup file created by
vgcfgbackup; I've elided the other logical volumes for brevity:
extra {
id = "vh30BJ-06Yt-uJTS-O5S4-ZyZc-r9vQ-Hfd7IU"
seqno = 7
status = ["RESIZEABLE", "READ", "WRITE"]
extent_size = 2097152 # 1024 Megabytes
max_lv = 0
max_pv = 0
physical_volumes {
pv0 {
id = "jNBJ7Y-wZ4r-IPyn-KLkP-xjdU-NRXu-f2yUBu"
device = "/dev/md7" # Hint only
status = ["ALLOCATABLE"]
pe_start = 384
pe_count = 224 # 224 Gigabytes
}
}
logical_volumes {
extra_disk {
id = "cTvMfD-XTIT-NQhs-vsnO-sgDq-ltXA-jVf0Pg"
status = ["READ", "WRITE", "VISIBLE"]
segment_count = 2
segment1 {
start_extent = 0
extent_count = 8 # 8 Gigabytes
type = "striped"
stripe_count = 1 # linear
stripes = [
"pv0", 130
]
}
segment2 {
start_extent = 8
extent_count = 48 # 48 Gigabytes
type = "striped"
stripe_count = 1 # linear
stripes = [
"pv0", 144
]
}
}
}
}
So to hack this up manually, you'd have to first verify that no segment extends
beyond the new end of the physical volume, and then reduce the pe_count in
the meta-data.
Best of luck,
Bill Rugolsky
