Mysql Error: too many open files

# error: ERROR 1018 (HY000): Can’t read dir of ‘.’ (errno: 24)

# Super user
$ sudo su

# See what mysql files are open
$ lsof -u mysql

# Count how many mysql files are open
$ lsof -u mysql | wc -l

# close mysql files
$ kill -9 `lsof -t -u mysql`

# sources
http://i-learnings.blogspot.com.br/2012/11/error-1018-hy000-cant-read-dir-of-errno.html
http://www.webhostingtalk.com/showthread.php?t=1138305

SNMP Getting Started

# install
sudo apt-get install snmp snmpd snmp-mibs-downloader

# configuration
# server
$ sudo nano /etc/snmp/snmpd.conf

rocommunity VegetaRocks
syslocation Vegeta planet 
sysContact Vegeta <vegeta@dbz.com>;

# restart snmpd
$ sudo /etc/init.d/snmpd restart

# Test. On client
$ snmpwalk -v1 -c VegetaRocks 192.168.0.13
$ snmpget -v1 -c VegetaRocks 192.168.0.13 1.3.6.1.4.1.2021.4.5.0

# example of traffic in wireshark
snmp traffic wireshar

# list of SNMP OID
http://www.debianadmin.com/linux-snmp-oids-for-cpumemory-and-disk-statistics.html

# sources