Disable Or Remove Gmail Account From Android

                           Go to Settings->Accounts & Sync and touch your gmail account. It will show you options of what you can sync (Books, Calendar, Contacts, Gmail, Music). Touch the Gmail one and it won't sync your gmail account with that device.

Change Sender Name In mailx

                                     For Changing the Default sender name (the default address like root) in mailx, use the  following syntax

Syntax:-mailx -s "Subject" To Mail Address -- -r From Mail Address -F “Sender Name”

Eg:-  mailx -s 'Disk Space Alert' itteam@gmail.com  -- -r ictops@aerl.in -F "ICTOPS"

Where

-s is the subject

-r is the reply address

-F is the Full name of the sender

Output :-

from:     ICTOPS

to:     jaganponnus@gmail.com,

        aneeshktramrita@gmail.com

date:     Mon, Nov 3, 2014 at 12:38 PM

subject:     Disk Space Alert

Change Sender Mail Address In mailx

                          For Changing the Default sender mail address (the default address like root@ubuntu.com) in mailx, use the  following syntax

Syntax:-mailx -s "Subject" To Mail Address -- -r From Mail Address

                            The Usage info shows "[-- sendmail-options ...]" and since "-r" is a sendmail option, you need to use the double dashes first.
Eg:- mailx -s 'Disk Space Alert' itteam@gmail.com -- -r ictops@aerl.in << EOF

Quickly Make A Large File In Ubuntu

If you want to create a 10 GB File, follow the steps below listed

root@ubuntu:~# time dd if=/dev/zero of=large bs=10G count=1

dd: memory exhausted by input buffer of size 10737418240 bytes (10 GiB)

real    0m0.002s

user    0m0.000s

sys     0m0.000s

root@ubuntu:~# du -B 1 --apparent-size large

0       large

root@ubuntu:~# du -B 1 large

0       large

root@ubuntu:~# time fallocate -l 10G large

real    0m0.091s

user    0m0.000s

sys     0m0.008s