MonthDecember 2012

Listing RPM file contents

Before installing a RPM file , atleast few will be curious to check what exactly that particular rpm files contains.

For this you can use the rpm command with qlp flags

The syntax is as below.
#rpm -qlp vim-minimal-7.0.109-7.el5.x86_64.rpm
warning: vim-minimal-7.0.109-7.el5.x86_64.rpm: Header V3 DSA signature: NOKEY, key ID 37017186

How Do I List Files For Installed Package?

# rpm -ql packageName
# rpm -ql samba
# rpm -ql httpd

Linux Add a Swap File – Howto

Step #1: Login as the Root User

Open a terminal window (select Applications > Accessories > Terminal) or login to remote server using the ssh client. Switch to the root user by typing su – and entering the root password, when prompted

Step #2: Create Storage File

Type the following command to create 512MB swap file (1024 * 512MB = 524288 block size):
# dd if=/dev/zero of=/swapfile1 bs=1024 count=524288


if=/dev/zero : Read from /dev/zero file. /dev/zero is a special file in that provides as many null characters to build storage file called /swapfile1.
of=/swapfile1 : Read from /dev/zero write stoage file to /swapfile1.
bs=1024 : Read and write 1024 BYTES bytes at a time.
count=524288 : Copy only 523288 BLOCKS input blocks.
Step #3: Set Up a Linux Swap Area

Type the following command to set up a Linux swap area in a file:
# mkswap /swapfile1

Setup correct file permission for security reasons, enter:
# chown root:root /swapfile1
# chmod 0600 /swapfile1

A world-readable swap file is a huge local vulnerability. The above command make sure only root user can read/write to the file. Finally, activate /swapfile1 swap space immediately, enter:
# swapon /swapfile1

To activate /swapfile1 after Linux system reboot, add entry to /etc/fstab file. Open this file using a text editor such as vi:
# vi /etc/fstab

Append the following line:
/swapfile1 swap swap defaults 0 0

Save and close the file. Next time Linux comes up after reboot, it enables the new swap file for you automatically.

How do I Verify Swap is Activated or Not?

Simply use the free command:
$ free -m

Samba 4 released

Samba is a free software licensed under GNU general public license and  re-implementation of the SMB/CIFS networking protocol. Samba version 4 has been released. It is a major rewrite that enables Samba to be an Active Directory domain controller.


Samba 4.0.0 Available for Download

The uncompressed tarballs and patch files have been signed using GnuPG (ID 6568B7EA). The source code can be downloaded now. See the release notes for more info and the press release.


From the release note:

Samba 4.0 supports the server-side of the Active Directory logon environment used by Windows 2000 and later, so we can do full domain
join and domain logon operations with these clients.

Our Domain Controller (DC) implementation includes our own built-in LDAP server and Kerberos Key Distribution Center (KDC) as well as the Samba3-like logon services provided over CIFS. We correctly generate the infamous Kerberos PAC, and include it with the Kerberos tickets we issue.

When running an AD DC, you only need to run 'samba' (not smbd/nmbd/winbindd), as the required services are co-coordinated by this master binary. The tool to administer the Active Directory services is called 'samba-tool'.

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