Particularly useful if you're mounting different drives, using the following command will allow you to see all the filesystems currently mounted on your computer and their respective specs with the added benefit of nice formatting. Show Sample Output
Curious about differences between /bin, /usr/bin, and /usr/local/bin? What should be in the /sbin dir? Try this command to find out. Tested against Red Hat & OS X
Ever ask yourself "How much data would be lost if I pressed the reset button?" Scary, isn't it? Show Sample Output
In my example, the mount point is /media/mpdr1 and the FS is /dev/sdd1 /mountpoint-path = /media/mpdr1 filesystem=/dev/sdd1 Why this command ? Well, in fact, with some external devices I used to face some issues : during data transfer from the device to the internal drive, some errors occurred and the device was unmounted and remounted again in a different folder. In such situations, the command mountpoint gave a positive result even if the FS wasn't properly mounted, that's why I added the df part. And if the device is not properly mounted, the command tries to unmount, to create the folder (if it exists already it will also work) and finally mount the FS on the given mount point. Show Sample Output
Create a temporary file that acts as swap space. In this example it's a 1GB file at the root of the file system. This additional capacity is added to the existing swap space. Show Sample Output
since fuse mounts do not appear in /etc/mtab (fuse can't write there, dunno if it would if it could) this is propably a better way.
Finds all directories containing more than 99MB of files, and prints them in human readable format. The directories sizes do not include their subdirectories, so it is very useful for finding any single directory with a lot of large files. Show Sample Output
This is just a proof of concept: A FILE WHICH CAN AUTOMOUNT ITSELF through a SIMPLY ENCODED script. It takes advantage of the OFFSET option of mount, and uses it as a password (see that 9191? just change it to something similar, around 9k). It works fine, mounts, gets modified, updated, and can be moved by just copying it. USAGE: SEE SAMPLE OUTPUT The file is composed of three parts: a) The legible script (about 242 bytes) b) A random text fill to reach the OFFSET size (equals PASSWORD minus 242) c) The actual filesystem Logically, (a)+(b) = PASSWORD, that means OFFSET, and mount uses that option. PLEASE NOTE: THIS IS NOT AN ENCRYPTED FILESYSTEM. To improve it, it can be mounted with a better encryption script and used with encfs or cryptfs. The idea was just to test the concept... with one line :) It applies the original idea of http://www.commandlinefu.com/commands/view/7382/command-for-john-cons for encrypting the file. The embedded bash script can be grown, of course, and the offset recalculation goes fine. I have my own version with bash --init-file to startup a bashrc with a well-defined environment, aliases, variables. Show Sample Output
Before doing this, back-up all data on any ext3 partitions that are to be converted to ext4.
After running previous command you MUST run fsck, is needed to return the filesystem to a consistent state.
fsck -pDf /dev/yourpartition
Edit /etc/fstab and change the 'type' from ext3 to ext4 for any partitions that are converted to ext4.
the middle command between the ; and ; is the vi commands that insert that line into the last line of the file, the esc with the carets is literally hitting the escape key, you have to have the smbfs package installed to do it, I use it to access my iTunes music on my mac from my linux PC's with amarok so I can play the music anywhere in the house. among other things, it allows you to access the files on that share from your computer anytime you're on that network.
To create directory, use:
tempdir=$(/bin/mktemp -d)
When a fs hangs and you've just one console, even # ls could be a dangerous command. Simply put a trailing "&" and play safe
Necessary for fsck for example. The remount functionality follows the standard way how the mount command works with options from fstab. It means the mount command doesn't read fstab (or mtab) only when a device and dir are fully specified. After this call all old mount options are replaced and arbitrary stuff from fstab is ignored, except the loop= option which is internally generated and maintained by the mount command. It does not change device or mount point.
use the locate command to find files on the system and verify they exist (-e) then display each one in full details. Show Sample Output
This one-liner is for cron jobs that need to provide some basic information about a filesystem and the time it takes to complete the operation. You can swap out the di command for df or du if that's your thing. The |& redirections the stderr and stdout to the mail command. How to configure the variables. TOFSCK=/path/to/mount FSCKDEV=/dev/path/device or FSCKDEV=`grep $TOFSCK /proc/mounts | cut -f1 -d" "` MAILSUB="weekly file system check $TOFSCK " Show Sample Output
Clone a root partition. The reason for double-mounting the root device is to avoid any filesystem overlay issues. This is particularly important for /dev. Also, note the importance of the trailing slashes on the paths when using rsync (search the man page for "slash" for more details). rsync and bash add several subtle nuances to path handling; using trailing slashes will effectively mean "clone this directory", even when run multiple times. For example: run once to get an initial copy, and then run again in single user mode just before rebooting into the new disk. Using file globs (which miss dot-files) or leaving off the trailing slash with rsync (which will create /mnt/target/root) are traps that are easy to fall into.
I added -S to du so that you don't include /foo/bar/baz.iso in /foo, and change sorts -n to -h so that it can properly sort the human readable sizes.
Not really alternative, just giving a different behavior listing current directory if no directory given.
XX is your device partition number like /dev/sdc1 .
to see how many inodes your partition have type:
df --inodes (or df -i)
Default formatting with ext4 would create small inode count for the new partition
if you need big count of inodes is the fstype news the correct one.
in debian you can see which fstype exists as template in:
vim /etc/mke2fs.conf
if you format default ext for a partition size with 1TB you would get 1 Million inodes (not enough for backupStorages)
but if you format with fstype news you would get hunderd of millions of inodes for the partition.
you have tune
/etc/sysctl.conf
also with following sysconfig parameters
fs.file-max = XXX
fs.nr_open = XXX
where XXX is the count of max inodes for whole system
Useful for analyzing disk usage. If you prefer GUI try http://en.wikipedia.org/wiki/Filelight or http://www.marzocca.net/linux/baobab/ Show Sample Output
Iozone with a file of 2GB, 64KB record size, write/rewrite and read/re-read test, using just one thread. Show Sample Output
commandlinefu.com is the place to record those command-line gems that you return to again and again. That way others can gain from your CLI wisdom and you from theirs too. All commands can be commented on, discussed and voted up or down.
Every new command is wrapped in a tweet and posted to Twitter. Following the stream is a great way of staying abreast of the latest commands. For the more discerning, there are Twitter accounts for commands that get a minimum of 3 and 10 votes - that way only the great commands get tweeted.
» http://twitter.com/commandlinefu
» http://twitter.com/commandlinefu3
» http://twitter.com/commandlinefu10
Use your favourite RSS aggregator to stay in touch with the latest commands. There are feeds mirroring the 3 Twitter streams as well as for virtually every other subset (users, tags, functions,…):
Subscribe to the feed for: