How to clean RAM cache in Linux

-
Check free and allocated RAM:
#free -m
total used free shared buffers cached
Mem: 3923 2504 1418 0 144 1882
-/+ buffers/cache: 478 3445
Swap: 0 0 0

Clean the cached RAM:
#sync; echo 3 > /proc/sys/vm/drop_caches

Check free and allocated RAM:
# free -m
total used free shared buffers cached
Mem: 3923 475 3448 0 3 99
-/+ buffers/cache: 373 3550
Swap: 0 0 0

Commenti

Posta un commento

Post popolari in questo blog

Solaris 10: How to restart network service without reboot

-
Adding or editing the IP address on a Solaris 10 server is different from the previous versions of the OS (Solaris 9, Solaris 8 etc). In the previous versions of the Solaris Operating System, you need to edit the /etc/hosts file and add/edit the entry for the IP address and the hostname. Example: 192.168.1.1 myhost However, in Solaris 10, you should edit the /etc/hosts file (a symlink to /etc/inet/hosts file) and the /etc/inet/ipnodes file and add an entry for IP address and hostname. Once done, restart the Network service using # svcadm restart network/physical or reboot the server for the changes to take effect. Although, the /etc/inet/ipnodes files is primarily for IPv6 only, without adding an entry to the file, the IP address (IPv4) doesn’t become active. This seems to be a known problem but the good news is this is now fixed in the Solaris 10 U4 (08/07 build). Also, ensure that the /etc/netmasks file with the network ID and the netmask.
Read more »

How to send e-mail using PHP and mail() with Linux Debian

-
Note: This is tested and proven to work on Debian Squeeze (stable) If you are a web-admin or a PHP developer hosting on your own servers you might have found out that PHP mail() function does not work out of the box in Debian unless you have installed Exim (default MTA for Debian Squeeze), sendmail or some other MTA. Most of the time this is OK, but when you really don't want to mix a mailserver with your webserver this is going to be a problem. In php.ini file there is a SMTP configuration value that you can set which is misleading. Even though you set the SMTP value, PHP mail() function will not connect directly to the SMTP server and relay emails rather it depends heavily on sendmail program which can be set via the sendmail_path configuration value. In conclusion you'll have to have a working sendmail program if you want to use PHP mail() function. So rather than using a complete MTA just to relay emails to your mailserver you can use SSMTP which is a send-only send
Read more »