Saiweb

The downside of a development server is … it’s for development.

It is  not always cost effective to have the exact same setup as you you have in your production environment …

Especially if you have a multi server setup.

So I find myself today moving /var/lib/mysql … being as the OS drive is very small, and pulling down a near 20GB database backup and then trying to rebuild the database on the same drive … well as you can imagine caused a few problems *doh*


/etc/init.d/mysql stop
mv /var/lib/mysql /raid_5/


So surely you just symlink … right?


ln -s /raid_5/mysql /var/lib/mysql
/etc/init.d/mysql start


Well then answer would be no … upon importing the backup


mysql < backup.sql
Can't create table './database/table.frm' (errno: 121)


A nice errorno: 121


/etc/init.d/mysql stop
rm -rf /var/lib/mysql
mkdir /var/lib/mysql
chown mysql:mysql /var/lib/mysql
mount --bind /raid_5/mysql /var/lib/mysql
/etc/init.d/mysql start


et voila …

Data directory is relocated and the import working smoothly. Feel free to suggest any “cleaner” methods.

UPDATE: Please rememeber to add the ‘mount’ line into your rc.local otherwise when you reboot this mount will be gone!

This is something I find myself having to do, more and more lately due to this VoIP roll out.

From windows (xp)

Start > run > cmd

Once the command window is open ping the IP address of the device (this forces your system to do an ARP request and store the device information in the cache, don’t ask me why but microsoft decided it was a good idea not to lookup the information if it isn’t allready in the cache!)

NOTE: Even if the device blocks ICMP, this should still work, run ettercap on your windows network to see just how many times you will see an ARP request along the lines of “WHO HAS xxx.xxx.xxx.xxx”.

Now to get the MAC address type


arp -a xxx.xxx.xxx.xxx


Where xxx.xxx.xxx.xxx is the IP address of the device you just pinged.


C:\Documents and Settings\buzz>arp -a 10.99.1.10

Please note this only works for a device on the same IP range.

If you run two ranges, i.e.

192.168.1.XXX

and

192.168.2.XXX

You will need to make the ARP request from a device bound to that range (servers are especially usefull here).