How do we create the Airwave database backup when we have all the following issues:
1. Available nightly backup on the server was created several days / weeks ago.
2. All the process are down due to insufficient disk space including postgresql.
3. Services will not start and backup command will not run due to insufficient disk space.
Executing any scripts which required db access will return the following.
[root@rraruba01 mercury]# dbsize
DBI connect('dbname=airwave','airwave',...) failed: could not connect to server: No such file or directory
Is the server running locally and accepting
connections on Unix domain socket "/tmp/.s.PGSQL.5432"? at /root/svn/mercury/lib/perl/Mercury/DB/Q.pm line 654
We can create backup only if we make some disk space available and that is possible since by default all server will have reserved disk space. Before we release the reserved disk space we need to disable amp so Airwave server doesn't come up and start utilizing the disk space.
# amp_disable
Please follow the below instruction to free up the reserved disk space.
Run the following command to find the volume directory as marked below.
[root@airwave764 mercury]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/VolGroup00-LogVol00
75G 5.5G 66G 8% /
tmpfs 2.9G 0 2.9G 0% /dev/shm
/dev/sda1 97M 36M 57M 39% /boot
> As per the above command derive the following command based on the VolGroup00-LogVol00 which is the path for the logical partition.
# tune2fs -m 1 /dev/VolGroup00/LogVol00
> Using the above command we will set the reserved-blocks-percentage to 1 from 5 and that will free up the reserve.
[root@airwave764a mercury]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/VolGroup00-LogVol00
75G 4.2G 67G 6% /
tmpfs 3.9G 0 3.9G 0% /dev/shm
/dev/sda1 97M 36M 57M 39% /boot
===========
[root@airwave764a mercury]# tune2fs -m 1 /dev/VolGroup00/LogVol00
tune2fs 1.41.12 (17-May-2010)
Setting reserved blocks percentage to 1% (198901 blocks)
===========
[root@airwave764a mercury]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/VolGroup00-LogVol00
75G 4.2G 70G 6% /
tmpfs 3.9G 0 3.9G 0% /dev/shm
/dev/sda1 97M 36M 57M 39% /boot
============
> Now it will provide additional 4% of available disk space using that we could force a database backup using the following command and export the backup file databackup.tar.gz from the /alternative directory.
# root; screen; amp_backup