** On Apr 27, w trillich scribbled:
> ever wonder what all those background processes are for?
>
> me too, and i still do. if you have some answers, please
> post them for us newbies.
>
> # ps t\?
> PID TTY STAT TIME COMMAND
> 1 ? S 0:06 init [2]
parent of all the processes in your system.
> 2 ? SW 0:00 [kflushd]
Not a "real" process - a kernel flush daemon (actually a kernel thread)
Runs periodically to flush the block device buffers
> 3 ? SW< 0:00 [kswapd]
Same as above, but for the swap activities. Synchronizes swap information.
> 4 ? SW 0:00 [md_thread]
> 5 ? SW 0:00 [md_thread]
You probably don't need these two. They're auto-mounter threads AFAIR
> 9757 ? S 0:00 /usr/sbin/apache
Your HTTP server.
> 1319 ? S 0:01 update
On newer kernels it's not needed anymore. Performs the same function (more
or less) as the above k*d daemons.
> 1885 ? S 0:00 /sbin/syslogd
System logger. Writes to files what applications send to the system log.
> 1887 ? S 0:00 /sbin/klogd
A partner to the above daemon which takes care of the kernel logging.
> 1894 ? S 0:00 /sbin/kerneld
Daemon to load the modules on demand. In newer kernels not needed anymore.
> 1897 ? S 0:01 /usr/sbin/named
Nameserver (a DNS server) - in that case it's BIND
> 1918 ? S 0:00 /usr/sbin/exim -bd -q30m
Your MTA (Mail Transport Agent) or, in M$ nomenclature, an SMTP server
> 2002 ? S 0:00 /usr/sbin/rwhod
RPC-based remote who server.
> 2001 ? S 0:00 /usr/sbin/rinetd
A version of inetd that redirects requests somewhere else than this machine.
> 2018 ? S 0:00 /usr/sbin/afpd -n server
> 2020 ? S 0:00 /usr/sbin/papd
Don't know these two :))
> 2026 ? S 0:00 proftpd (accepting connections)
ProFTPD ftp server running in standalone mode
> 2031 ? S 0:00 /usr/sbin/atd
Scheduled job spooler (for the 'at' command)
> 9758 ? S 0:00 /usr/sbin/apache
> 9756 ? S 0:01 /usr/sbin/apache
> 9759 ? S 0:00 /usr/sbin/apache
> 9760 ? S 0:00 /usr/sbin/apache
> 9761 ? S 0:00 /usr/sbin/apache
Clones of the parent (above) HTTPD process. Apache is a multi-process
architecture server.
> 2206 ? S 0:00 /sbin/portmap
Portmapper for the RPC-based services (kinda a dispatch for them)
> 2215 ? S 0:00 /usr/sbin/inetd
The "normal" internet superserver. It takes care of starting your services
that aren't ran in the standalone mode.
> 5922 ? S 0:00 /usr/sbin/cron
A cronjob server. Something like a scheduler but a periodic one, unlike atd
which executes something 'at point' - once.
[snip]
> inetd = listens for network connections & hands them off
> to appropriate processes
> proftpd = ftp server
> apache = httpd server
> named = dns nameserver (xlate 'www.site.org' to '123.45.678.90')
> exim = email stuff
> cron = periodic script-runner (try "crontab -e")
> atd = like cron; but for running scheduled 'at <time>' commands
> update = flushes disk buffers now & then so if ever you crash
> (remember windows? macos?) you'll lose less.
>
> these i can GUESS at:
>
> *logd = system loggers:
> syslogd and klogd both log important messages to your log files.
> we need them _both_ because... well... um...
Because syslogd handles the userspace messages, klogd handles the kernel
messages.
> kerneld = linux 2.0 and earlier--some voodoo regarding modules
> (dynamic module loading in 2.1+ [aka 'kmod'] makes this obsolete?)
yup
> rwhod = server for 'whois bubba@edu.org.com'
useless crap (IMHO)
> rinetd = like inetd, but different?
nah, a redirector - do you really need it?
> afpd = portion of appletalk network protocols, maybe?
> papd = some more appletalk stuff?
hmm, dunno, perhaps? :)
> portmap = something to do with Remote-Procedure-Call?
precisely
marek
Attachment:
pgpyDFbYOlbak.pgp
Description: PGP signature