Linux
Mount SMB Share
mount -t smbfs -o username=uname,password=passwd //smbserv/share /destination
Label fat32 vfat Filesystem
mlabel -i /dev/sdc1 ::FOOBAR
ACL
setfacl -m u:foo:r-- DEST
setfacl -x u:foo DEST
setfacl -m g:bar:r-- DEST
setfacl -x g:bar DEST
setfacl -m d:u:foo:r-- DIR
setfacl -m d:g:bar:r-- DIR
setfacl -m m:r-- DEST
setfacl -m d:m:r-- DIR
setfacl -x u:foo DEST
setfacl -m g:bar:r-- DEST
setfacl -x g:bar DEST
setfacl -m d:u:foo:r-- DIR
setfacl -m d:g:bar:r-- DIR
setfacl -m m:r-- DEST
setfacl -m d:m:r-- DIR
Archiving / Backup
Backup Remotehost with tar
ssh root@otherhost -c blowfish 'cd /YOURPATH; tar -f - -p -P -c --exclude=/YOURPATH/tmp --exclude=/YOURPATH/var/cache /' | dd of=/daten/backup.tar
Add redundancy to files
par2 create myparfiles foo*
Create a DVD image larger than 2GB
mkisofs -udf -allow-limited-size -o foo.img foo
Complete Compressed Partionbackup Into an Image
mount /dev/hda1 / -o remount,rw;
dd if=/dev/zero of=/delme1 bs=4048; rm /delme1;
mount /dev/hda1 / -o remount,ro;
dd if=/dev/zero of=/delme1 bs=4048; rm /delme1;
mount /dev/hda1 / -o remount,ro;
Local
dd if=/dev/hda1 bs=4048 | bzip2 > /mountpoint/image_hda1.bz;
Remote
ssh host -c blowfish 'dd if=/dev/hda1 bs=4048 | bzip2' | dd of=/image_hda1.bz
Detect interactive shells
if shopt -q login_shell ; then
...
else
...
fi
...
else
...
fi
Change output of a shellscript and restore output again later
exec 3>&1
exec 1>>/var/log/mylogfile.txt
...
exec 1>&3
exec 3>&-
exec 1>>/var/log/mylogfile.txt
...
exec 1>&3
exec 3>&-
Change file content without temporary files with sponge
Usually you have to use temporary files if you want to change the content of a file, as you can not read and write to a file simultaneously. This can be very inconvenient, especially as secure creation of temp files is not too easy. One solution for this problem is sponge:
cat foo.txt | sed s/t/T/ | sponge foo.txt
However, this does only work if sponge writes to a file. If you redirect its output this will not work. In Debian sponge can be found in the moreutils package.
System Infos
# free -m
# df -ah
# top -n1
htop
# vmstat 5 3
smartctl --all /dev/sda
memstat -w
# df -ah
# top -n1
htop
# vmstat 5 3
smartctl --all /dev/sda
memstat -w
Who blocks a mounted drive
If you can not unmount a mounted drive find out who blocks it
lsof +D /mnt/foo
fuser /mnt/foo
fuser /mnt/foo
Benchmarks
Use zcav to measure the speed of a mass storage device depending on the position on the drive you are currently reading from
zcav /dev/sdb > zcav.txt
gnuplot
set yrange [0:*]
set format y '%g Blocks/s'
set format x '%g MB'
plot "zcav.txt" using 1:2 title "Foo"
gnuplot
set yrange [0:*]
set format y '%g Blocks/s'
set format x '%g MB'
plot "zcav.txt" using 1:2 title "Foo"
Benchmark a drive with bonnie++
bonnie++ -u root -d /mnt/mnt/
Networks
Show which settings the networkmanager is using, for example show DNS server that is being used
nmcli dev show