Migrate mysql users to another server

ERROR 1577 (HY000) at line 1: Cannot proceed because system tables used by Event Scheduler were found damaged at server start ERROR 1547 (HY000) at line 1: Column count of mysql.proc is wrong. Expected 20, found 16. The table is probably corrupted


solution:
sudo mysql_upgrade -uroot -p --force

Rsync and sudo over SSH

backup_user ALL=(root)NOPASSWD:/usr/bin/rsync

rsync --rsync-path="sudo rsync" backup_user@myhosttobackup.net:/root /backup_directory

debian Add a second hard disk

fdisk -l

cfdisk /dev/sdb

mkfs.ext3 /dev/sdb1

mkdir /disk2
mount -t ext3 /dev/sdb1 /disk2

/etc/fstab
/dev/sdb1 /disk2 ext3 defaults,errors=remount-ro 0 1 

error: 'Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock'

error: 'Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock'

in my case
my solution is simply comment out skip-bdb
Berkeley DB is no longer in 5.1x, so the option doesn't apply any more

debian no sound

lsof /dev/snd/*

to find out what program are using sound device, some program might be hanging causing sound not to function

linux grep and sed to find through files and replace a string

grep -rl oldstring path | xargs sed -i 's/oldstring/newstring/g

find /path -type f -exec sed -i 's/oldstring/newstring/g' {} \;

jQuery wait for all images to load before executing

$(window).load(function() {
    // do your thing here
});