Commands tagged System Administration (11)

  • Run a file system check on your next boot.

    The empty file /forcefsck causes the file system check fsck to be run next time you boot up, after which it will be removed. This works too: sudo >/forcefsck


    38
    sudo touch /forcefsck
    johnraff · 2009-10-29 17:04:47 17
  • List all files opened by a particular command

    List all file opened by a particular command based on it's command name. Show Sample Output


    25
    lsof -c dhcpd
    d4n3sh · 2009-04-17 07:18:38 11
  • List files opened by a PID

    Lis all files opened by a particular process id. "PID" Show Sample Output


    6
    lsof -p 15857
    d4n3sh · 2009-04-17 07:16:03 5
  • Don't spam root. Log your cronjob output to syslog

    This command will log the output of your simple cronjobs to syslog, and syslog will take it from there. Works great for monitoring scripts which only produce simple output. Advantages: * This can be used by regular users, without modifying system files like /etc/syslog.conf * Reduce cron spam to root@localhost (Please stop spaming the sysadmins) * Uses common tools like syslog (and logrotate) so that you don't need to maintain yet another krufty logfile. * Still ensures that the output is logged somewhere, for posterity. Perhaps it's stored the secure, central syslog server, for example. * Seems to work fine on Ubuntu, CentOS, FreeBSD & MacOSX Show Sample Output


    6
    */5 * * * * root /usr/local/nagios/sbin/nsca_check_disk 2>&1 |/usr/bin/logger -t nsca_check_disk
    StefanLasiewski · 2010-07-02 00:47:05 7
  • Listing package man page, services, config files and related rpm of a file, in one alias

    Many times I give the same commands in loop to find informations about a file. I use this as an alias to summarize that informations in a single command. Now with variables! :D Show Sample Output


    2
    fileinfo() { RPMQF=$(rpm -qf $1); RPMQL=$(rpm -ql $RPMQF);echo "man page:";whatis $(basename $1); echo "Services:"; echo -e "$RPMQL\n"|grep -P "\.service";echo "Config files:";rpm -qc $RPMQF;echo "Provided by:" $RPMQF; }
    nnsense · 2015-05-11 16:46:01 13
  • turn off auto hard disc boot scanning for ext3


    1
    tune2fs -c -1 -i 0 /dev/VG0/data
    christian773 · 2010-05-29 08:20:35 3
  • create random numbers within range for conjob usage

    if you need to install cron jobs in a given time range. Show Sample Output


    1
    H=$(until ([ $i -le 6 -a $i -gt 0 -o $i -le 23 -a $i -gt 21 ] ); do i=$(date +%N | cut -c8-10); done ; echo $i) ; M=$(until [ $i -le 59 ]; do i=$(date +%N | cut -c8-10); done ; echo $i) ; echo $M $H \* \* \* backup-rsync-push.sh
    christian773 · 2010-05-29 08:42:43 6
  • Which .service related this file?

    I use this as an alias to get all .service files related a single installed file/conf (if it has services, of course). For rpm based systems ;) Show Sample Output


    1
    qf2s() { rpm -ql $(rpm -qf $1)|grep -P "\.service"; }
    nnsense · 2015-05-11 16:32:16 9
  • Manage "legacy" service run control links

    Change run control links from start "S" to stop "K" (kill) for whatever run levels in curly braces for a service called "myservice". NEWFN variable is for the new filename stored in the in-line shell. Use different list of run levels (rc*.d, rc{1,3,5}.d, etc.) and/or swap S with K in the command to change function of run control links. Show Sample Output


    0
    sudo find /etc/rc{1..5}.d -name S99myservice -type l -exec sh -c 'NEWFN=`echo {} | sed 's/S99/K99/'` ; mv -v {} $NEWFN' \;
    zoomgarden · 2010-01-03 00:56:57 4
  • manually set system date/time

    date MMDDhhmmYYYY date MMDDhhmm # example 27.12.1975 08:00 date 122708001975 Show Sample Output


    -1
    date MMDDhhmmYYYY
    christian773 · 2010-05-29 08:26:13 3
  • show system installation date


    -3
    tune2fs -l $(df -P / | tail -n1 | cut -d' ' -f1 ) | grep 'Filesystem created:'
    christian773 · 2010-05-29 08:15:25 4

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Checks throughput between two nodes
This will show the throughput between two nodes. Thanks to szboardstretcher, who posted it here: http://www.linuxquestions.org/questions/linux-networking-3/quick-and-easy-way-to-measure-throughput-between-two-nodes-868998/

Convert seconds to [DD:][HH:]MM:SS
Converts any number of seconds into days, hours, minutes and seconds. sec2dhms() { declare -i SS="$1" D=$(( SS / 86400 )) H=$(( SS % 86400 / 3600 )) M=$(( SS % 3600 / 60 )) S=$(( SS % 60 )) [ "$D" -gt 0 ] && echo -n "${D}:" [ "$H" -gt 0 ] && printf "%02g:" "$H" printf "%02g:%02g\n" "$M" "$S" }

remove comments (even those starting with spaces), empty lines (even those containing spaces) in one grep command
useful for discarding even those comments which start with blanks or those empty lines which contain blanks

Customer Friendly free
makes more sense to customers XD

positions the mysql slave at a specific master position
say you want to reinitialize the slave database without resetting the master positions. You stop the slave, dump the master database with --master-data=2 then execute the command on the slave and wait for it to stop at the exact position of the dump. reinit the slave db and start the slave. enjoy.

Replace + Find

python - covert image to base64 string for data URI use
useful if you are using lots of data URI's in your css files

Network traffic on NICs in mbps without sar, iperf, etc...
Need output in mbps (bits) # ./bytes-second.sh eth0 eth0 interface maximum Speed: 1000Mb/s RX:12883212 TX:17402002 B/s | RX:98 TX:132 Mb/s RX:12371647 TX:17830111 B/s | RX:94 TX:136 Mb/s RX:12502750 TX:17860915 B/s | RX:95 TX:136 Mb/s

Rapidly invoke an editor to write a long, complex, or tricky command
Next time you are using your shell, try typing $ ctrl-x ctrl-e # in emacs mode or $ v # in vi mode The shell will take what you've written on the command line thus far and paste it into the editor specified by $EDITOR. Then you can edit at leisure using all the powerful macros and commands of vi, emacs, nano, or whatever.

a function to find the fastest DNS server
http://public-dns.info gives a list of online dns servers. you need to change the country in url (br in this url) with your country code. this command need some time to ping all IP in list.

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