Csdrhrt

Need to clone a 400gb pool onto another machine. Will this work?
First I collect the data about the existing pool:

[root@oktest-prod-db-2 ~]# lvdisplay --units B vg_oktestdb2/pool

  --- Logical volume ---

  LV Name                pool

  VG Name                vg_oktestdb2

  LV UUID                tPfUzG-bHW2-jepz-1Sf6-BSmw-jKz4-Tf6djR

  LV Write Access        read/write

  LV Creation host, time oktest-db-2, 2015-03-31 18:55:17 +0300

  LV Pool transaction ID 134

  LV Pool metadata       pool_tmeta

  LV Pool data           pool_tdata

  LV Pool chunk size     262144 B

  LV Zero new blocks     yes

  LV Status              available

  # open                 0

  LV Size                474031849472 B

  Allocated pool data    10.16%

  Allocated metadata     7.66%

  Current LE             113018

  Segments               1

  Allocation             inherit

  Read ahead sectors     auto

  - currently set to     256

  Block device           253:5

Then create a new pool with the same size:

[root@oktest-prod-db-1-new ~]# lvcreate -L 474031849472b -T vg_oktestdb1/pool --chunksize 256k

  Logical volume "lvol0" created

  Logical volume "pool" created

And lastly copy it over ssh:

[root@oktest-prod-db-2 ~]# dd bs=128k if=/dev/mapper/vg_oktestdb2-pool | ssh root@oktest-prod-db-1-new 'dd bs=128k of=/dev/mapper/vg_oktestdb1-pool'

Now I just sit and wait for several hours

Upd: it did work back then.

Not sure how it goes trough a pipe to a SSH session, but I'm used to do this with netcat

first launch a listening netcat on the destination server :

netcat -p 1237 -l | dd of=<destination lv path/name> obs=$((1024*1024)) ibs=8192

Then on the source server

dd ibs=$((1024*1024)) obs=8192 <source lv path/name>  | pv | netcat <ip of destination server> 1237

you can skip the "pv" part of course and change the port "1237" to whatever will pass trough your firewalls.

Also you can pipe it into gzip but from my experience this is not a big
gain.