ossdb-snapshot, lvm database snapshot tool

Just tossing this out there on the chance it might be useful for others. This script, dubbed ossdb-snapshot, is based on the mysql-snapshot tool from Jeremy Cole. The idea is to simplify management of lvm snapshots for purposes of creating postgresql snapshot style backups (I’ve left the mysql pieces in place in case anyone wants to make it a truely cross-db app), either for backup or pitr setup. Quick example after the jump. In this system, the lvm setup on the master looks something like this:


[root@luigi ~]# lvdisplay
  --- Logical volume ---
  LV Name                /dev/pipedbvg2/pipedbdata
  VG Name                pipedbvg1
  LV Write Access        read/write
  LV Status              available
  LV Size                185.00 GB
  Current LE             47360
  Block device           253:0

  --- Logical volume ---
  LV Name                /dev/pipedbvg2xl/pipedbxlog
  VG Name                pipedbvg1xl
  LV Write Access        read/write
  LV Status              available
  LV Size                27.00 GB
  Current LE             6912
  Block device           253:1



Basically we want to grab a copy of postgresql using the start/stop backup commands, mounting our lvm snapshot at /pipedb/pitr so we can copy it to another box. The commands look something like this:

[root@luigi ~]# ./ossdb-snapshot --dbtype pgsql -u postgres -p password -c --origin-lv pipedbdata --origin-vg pipedbvg2 --snapshot-name pgpitr --snapshot-size 20GB --mountpoint /pipedb/pitr

[root@luigi ~]# lvdisplay
  --- Logical volume ---
  LV Name                /dev/pipedbvg2/pipedbdata
  VG Name                pipedbvg2
  LV Write Access        read/write
  LV snapshot status     source of
                         /dev/pipedbvg2/pgpitr [active]
  LV Status              available
  LV Size                185.00 GB
  Current LE             47360
  Block device           253:0

  --- Logical volume ---
  LV Name                /dev/pipedbvg2/pgpitr
  VG Name                pipedbvg2
  LV Write Access        read/write
  LV snapshot status     active destination for /dev/pipedbvg2/pipedbdata
  LV Status              available
  LV Size                185.00 GB
  Current LE             47360
  COW-table size         20.00 GB
  COW-table LE           5120
  Allocated to snapshot  0.00%
  Snapshot chunk size    8.00 KB
  Block device           253:2

  --- Logical volume ---
  LV Name                /dev/pipedbvg2xl/pipedbxlog
  VG Name                pipedbvg2xl
  LV Write Access        read/write
  LV Status              available
  LV Size                27.00 GB
  Current LE             6912
  Block device           253:1

[root@luigi pitr]# rsync -a --progress --delete --exclude='postmaster.pid' --exclude='postgresql.conf' --perms /pipedb/pitr/ mario:/pipedb/data/

[root@luigi ~]# ./ossdb-snapshot -d --origin-vg pipedbvg2 --snapshot-name pgpitr


The above works fine in my setup for doing pitr setups, if you have a different setup or need, you might need to adjust things accordingly.