How to install iftop in Linux servers

iftop is a command line tool that shows a list of active network connections between local host and any remote host, sorted by their bandwidth usage. The list of top-ranking network connections (in terms of bandwith usage) is periodically refreshed in a text-based user interface. Using iftop, you can visually check the bidirectional bandwidth usage of different network connections in real time. In order to install iftop on Linux, follow the instructions below.

If you would like to build and install the latest version of iftop manually, do the following.
$ yum -y install ncurses-devel libpcap-devel
$ wget http://www.ex-parrot.com/~pdw/iftop/download/iftop-0.17.tar.gz
$ tar xvfvz iftop-0.17.tar.gz
$ cd iftop-0.17
$ ./configure
$ make
$ make install

How to clear eximstats db

If the size of your eximstats database is getting large, you can do the following steps to clear it.

Login to mysql

mysql

mysql> use eximstats
mysql> delete from sends;
mysql> delete from smtp;
mysql> delete from failures;
mysql> delete from defers;

You can also use the following steps.

mysqladmin drop eximstats

mysqladmin create eximstats

mysql eximstats < /usr/local/cpanel/etc/eximstats_db.sql

cPanel spamd resource consumption high

Spamd is one the highest resource consumer on a cPanel server. It allocates a lot of memory from the get-go and holds on to it throughout. There is a way to limit the number of spamd processes that are spawned. On a cPanel server, which is what this guide covers, there is a configuration file called /etc/cpspamd.conf with the following lines:


maxspare=1
maxchildren=3


For a leaner server. we recommend dropping maxchildren to 1 and maxspare to 1. This will save a good hundred of megs of memory. Don’t forget to restart exim for these changes to take effect.

To check Which process hogging the CPU

ps -eo pcpu,pid,user,args | sort -k 1 -r | head -10

Server Sending Spam at 127.0.0.1

Comment the following lines.

dnl # Uncomment and edit the following line if your outgoing mail needs to

dnl # be sent out through an external mail server:

dnl #

dnl # define(`SMART_HOST', `127.0.0.1')dnl

dnl #

Since  sendmail daemon accepts mail on 127.0.0.1. Your php script submits email there, or forks the sendmail executable which in turn submits email there (check your submit.mc / submit.cf to verify this)

Also The emails were all from nobody@myhost

Find all processes that is running as nobody:

ps -U nobody

SMTP connection from [127.0.0.1]:36667 (TCP/IP connection count = 1)

Run netstat under watch to see which process is connecting to port 25:

watch 'netstat -na | grep :25'

These steps can help you find out the culprit is the... web server. Then you can run a strace to see which script is called when an email is sent:

strace -f -e trace=open,stat -p 1234 -o wserver.strace

(1234 is the parent PID of the web server process)

 

svc: warning: unable to control /service/proftpd/log: supervise not running

if u ever found this error on FreeBSD  try this command then

 svc: warning: unable to control /service/proftpd/log: supervise not running

# svscanboot &

Free BSD- shell error /var: create/symlink failed, no inodes free

Fix For   /var: create/symlink failed, no inodes free in Shell -- FreeBSD


buraglio@rtr%  umount -f /var
buraglio@rtr%  fsck -y -f /dev/ad1s1f
** /dev/ad1s1f
** Last Mounted on /var
** Phase 1 - Check Blocks and Sizes
** Phase 2 - Check Pathnames
** Phase 3 - Check Connectivity
** Phase 4 - Check Reference Counts
** Phase 5 - Check Cyl groups
FREE BLK COUNT(S) WRONG IN SUPERBLK
SALVAGE? yes

605 files, 2203376 used, 7039334 free (782 frags, 879819 blocks, 0.0% fragmentation)

***** FILE SYSTEM WAS MODIFIED *****


buraglio@rtr%  mount /dev/ad1s1f /var/