mongodb backup with zfs

http://www.mongodb.org/display/DOCS/fsync+Command

use admin
switched to db admin
> db.runCommand({fsync:1,lock:1})
{
 \"info\" : \"now locked against writes\",
 \"ok\" : 1
}
> db.currentOp()
{
 \"inprog\" : [
 ],
 \"fsyncLock\" : 1
}

> // do some work here: for example, snapshot datafiles...
/sbin/zfs/snapshot /mongo/mongo1@backup

> db.$cmd.sys.unlock.findOne();
{ \"ok\" : 1, \"info\" : \"unlock requested\" }
> // unlock is now requested.  it may take a moment to take effect.
> db.currentOp()
{ \"inprog\" : [ ] }

[Database]
server: localhost
user: root
password: pass
port: 27017

[ZFS]
zfs_command: /usr/sbin/zfs

; ZFS filesystem containing the MongoDB database files.
db_fs_name: mongo
db_fs_dir: /mong

import ConfigParser
import sys,os,time,commands,re

from optparse import OptionParser
from os.path import exists

from pymongo.connection import Connection
from pymongo.son import SON


txt_program_revision = \"0.1\"
txt_program_name = \"MoBack\"

args_parser = OptionParser(usage=\"%prog --filename MoBack.cfg -d directory\", version=txt_program_name + \" \" + txt_program_revision)
args_parser.add_option(\"-f\", \"--filename\", dest=\"FN_CONFIG\",help=\"Configuration file containing MONGODB and ZFS settings to use for backup run.\")
args_parser.add_option(\"-d\", \"--directory\", dest=\"DIRECTORY\",help=\"Copy backup to directory\")
args_parser.add_option(\"-N\", \"--no-destroy\", dest=\"NODESTROY\",action=\"store_true\", help=\"Ceated snapshot will be not destroyed.\",default=False )

arg_program_options, arg_leftover = args_parser.parse_args()

if arg_program_options.FN_CONFIG==None:
    print \"\\nMust supply a configuration filename. Please use --help for syntax.\"
    sys.exit(-1)

if arg_program_options.DIRECTORY==None:
    print \"\\nMust supply a directory where snapshot will send. Please use --help for syntax.\"
    sys.exit(-1)

### Load in configuration settings
config_parser = ConfigParser.SafeConfigParser()
try:
    f_config = open(arg_program_options.FN_CONFIG)
except IOError, e:
    print \"\\nCannot find \" + arg_program_options.FN_CONFIG + \". Please check the argument and try again.\"
    sys.exit(-2)

backup_dir = None
if not exists( arg_program_options.DIRECTORY):
    print \"\\nDirectory \" + arg_program_options.FN_CONFIG + \" don\'t exist. Please check the argument and try again.\"
    sys.exit(-2)
else:
    backup_dir = arg_program_options.DIRECTORY


config_parser.readfp(f_config)

# Validate individual required options
try:
    database_server= config_parser.get(\"Database\",\"server\")
    database_user  = config_parser.get(\"Database\",\"user\")
    database_pass  = config_parser.get(\"Database\",\"password\")
    database_port  = config_parser.get(\"Database\",\"port\")

    fn_zfs_cmd = config_parser.get(\"ZFS\",\"zfs_command\")
    fn_zfs_db_fs = config_parser.get(\"ZFS\",\"db_fs_name\")
    fn_zfs_db_fs_dir  = config_parser.get(\"ZFS\",\"db_fs_dir\")
except ConfigParser.NoOptionError, e:
    print \"\\n\" + repr(e)
    print \"Please make sure all required sections and options are supplied and try again.\"
    f_config.close()
    sys.exit(-3)

zfs_list_status, zfs_list_output  = commands.getstatusoutput(fn_zfs_cmd + \" list\")
if not re.compile(fn_zfs_db_fs).search(zfs_list_output, 1):
    print \"\\nNo ZFS DB filesystem named \" + fn_zfs_db_fs + \" exists. Please check your configuration and try again.\"
    sys.exit(-4) 
print \"\\nAll specified ZFS filesystems are present.\"


print \"\\n\\nMoBack is connecting to MongoDB:\"

try:
    connection = Connection( database_server , int(database_port))
    db = connection[\'admin\']
    db.authenticate(database_user, database_pass)
except:
    print \"Unable to connect to MySQL server \" + database_server + \". Please check the configuration file and try again.\"
    sys.exit(-5)

print \"\\tConnected to \" + database_server + \".\"

time_snapshot = \'auto-\'+ time.strftime(\"%Y-%m-%d_%H%M%S\")

print \"\\tPrepared MongoDB to ensure  consistency.\"
loc_cmd = SON()
loc_cmd[\'fsync\'] = 1
loc_cmd[\'lock\'] = 1
res = db.command(loc_cmd)

### Pull ZFS snapshots.
try:
    # Snapshot DB
    snap_name = fn_zfs_db_fs + \"@\" + time_snapshot
    print \"\\tSnapping ZFS DB filesystem.\"
    zfs_dbsnap_status, zfs_dbsnap_output = commands.getstatusoutput(fn_zfs_cmd + \" snapshot \" + snap_name)
    if zfs_dbsnap_status != 0:
        print \"An error occurred while executing the ZFS snapshot on \" + _fn_zfs_db_fs + \". Unlocking collections and quitting.\"
        coll = db[\'$cmd.sys.unlock\']
        coll.findOne()
        sys.exit(-7)
except:
    coll = db[\'$cmd.sys.unlock\']
    coll.findOne()
    print \"\\tAn unrecoverable error occurred while trying to pull the snapshots. We have unlocked the collections. Please check your system logs for details as to the ZFS error.\"
    sys.exit(-7)

print \"\\tUnlocking collections.\"
coll = db[\'$cmd.sys.unlock\']
coll.findOne()
print \"\\tcollections unlocked.\"
print \"MoBack snapshot run completed.\"

print \"\\n\\nSnapshots created:\"
print \"\\t\" + fn_zfs_db_fs + \"@\" + time_snapshot
sys.exit( 0)


if backup_dir:
    zfs_backsend_status, zfs_backsend_output = \\
        commands.getstatusoutput(fn_zfs_cmd + \" send \" + snap_name + \" > \"  + backup_dir +\"/\"+  _database_server+\"_\"+database_port+\"_\"+time_snapshot)

if zfs_backsend_status != 0:
    print \"\\nAn error occurred while executing the ZFS send on \" + fn_zfs_db_fs + \".\"
    print zfs_backsend_output
    sys.exit(-7)


if arg_program_options.NODESTROY != True:
    snap_re = re.compile(r\'@auto\\-\')
    if not snap_re.search(snap_name):
        print \"\\n\\nBad snapshot name.\"
        sys.exit(-1)

    print \"\\n\\nScript is going to destroiy snapshot \"+ snap_name +\".\"
    zfs_dbsdestroy_status, zfs_dbsdestroy_output = commands.getstatusoutput(fn_zfs_cmd + \" destroy \" + snap_name)
    if zfs_dbsdestroy_status != 0:
        print \"\\nAn error occurred while executing the ZFS destroy on \" +  snap_name + \".\"
        print zfs_dbsdestroy_output
        sys.exit(-7)
    print \"\\n\"+ snap_name +\" destroyed.\" 

ZFS has many problems with fragmentation.