File Fragmentation checking on Linux

To find file fragmentation information for a specific file,we can use filefrag command.
filefrag reports on how badly fragmented a particular file. It makes allowances for indirect blocks for ext2 and ext3 filesystems, but can be used on files for any filesystem.

syntax:

filefrag -v (filename)

# filefrag -v /home/example/example.txt

-v   => verbose when checking for file fragmentation

ouptput:(for example)

Checking example.txt
Filesystem type is: ef53
Filesystem cylinder groups is approximately 606
Blocksize of file example.txt is 4096
File size of example.txt is 1194 (1 blocks)
First block: 7006588
Last block: 7006588
example.txt: 1 extent found

Command to check UUID

In your /etc/fstab file, you have have seen an entry that looks UUID=c81355eb-96d2-458a-8ce0-3fa12a04cb8e instead of a more familiar disk drive designation, such as /dev/hda1. Such entries are called universally unique identifiers (UUID). You can use these 128-bit numbers to make hard disk management easier.

This following command is used to print the UUID for a device. This may be used with UUID= in /etc/fstab to name devices that works even if disks are added and removed. redhat uses this in /etc/fstab file.

Print UUID to a selected  partition /dev/sda1

#blkid -o value -s UUID /dev/sda1

Print all UUIDs

#blkid -o value -s UUID

Strange Linux Commands Stands For

awk = "Aho Weinberger and Kernighan"
            This language was named by its authors, Al Aho, Peter Weinberger and Brian Kernighan.

cat = "CATenate"
The cat command is a standard Unix program used to concatenate and display files. The name is from catenate, a synonym of concatenate.

grep = "Global Regular Expression Print"
    grep comes from the ed command to print all lines matching a certain pattern g/re/p where re is a regular expression.

    fgrep = "Fixed GREP"
    fgrep searches for fixed strings only. The "f" does not stand for "fast" - in fact, "fgrep foobar *.c" is usually slower than "egrep foobar *.c"
   
    egrep = "Extended GREP"
   
nroff = "New ROFF"
troff = "Typesetter new ROFF"
    These are descendants of "roff", which was a re-implementation of the Multics "runoff" program (a program that you'd use to "run off" a good copy of a document)

tee = T
    From plumbing terminology for a T-shaped pipe splitter.

Perl = "Practical Extraction and Report Language"
Perl = "Pathologically Eclectic Rubbish Lister"
    The Perl language is Larry Wall's highly popular freely-available completely portable text, process, and file manipulation tool that bridges the gap between shell and C programming.