Tuesday, March 29, 2011

Download RPM packages from a YUM repo without installing in RHEL

Download RPM packages using YUM


This how-to will explain how to download rpm packages from a yum repository without installing them. This will work on Redhat Enterprise Linux 5.x, Fedora and CentOS 5.x.

You need to install yum plugin called yum-downloadonly. This plugin adds a --downloadonly flag to yum so that yum can download the packages without installing/updating them. Following options supported by this plugin:

  • --downloadonly : don't update, just download a rpm file to default yum cache directory /var/cache/yum/.
  • --downloaddir=/path/to/dir : specifies an alternate directory to store packages such as /tmp
Install the yum-downloadonly plugin:

Type the following command to install plugin, enter:

        # yum install yum-downloadonly

Now for downloading rpm packages from an already configured yum repository use the following command:

      # yum update httpd -y --downloadonly

Friday, February 4, 2011

TCP Wrappers: Securing Linux


This how-to describes configuring TCP Wrappers for providing Access Control for the supported services in a Linux box.TCP wrappers are supported by most of the Linux distributions such as Redhat Enterprise Linux, Ubuntu, SUSE, Debian, BSD and UNIX. TCP Wrappers work in the manner of a host-based Access Control List. They will allow host or network addresses to be used as indicators to filter and implement a layer of access control. They additionally extend the capabilities of xinetd-controlled daemons. By using this technique, connection attempts can be logged, restricted, and messages returned. This can add an extra layer of security in your environment. TCP Wrappers also allow run-time reconfiguration without restarting or reloading the services they protect.

Mount NTFS partition in Linux

Mount NTFS partition in Redhat Enterpris Linux / Ubuntu Linux


Enterprise Linux distributions like Redhat Enterprise Linux ( RHEL ) does not provide native support to Windows NTFS partitions. However you may wand to mount a NTFS formated partiiton in your RHEL box. Here is a simple howto to mount NTFS partitions in your RHEL box.

First of all you need to install a couple of packages. You can use YUM for installing the packages. The rpmforge yum repo contains required rpm packages for mounting NTFS partitions on Linux server. The packages are fuse and fuse-ntfs-3g.

              # yum install fuse fuse-ntfs-3g
Yes, you are done now you can mount ntfs partitions on your rhel server using the mount commandas follows.

             # mount -t ntfs-3g /dev/device-name /mount-point

For example:
           # mount -t ntfs-3g /dev/sdb1 /media

This one also works!!!!!

          # mount.ntfs-3g /dev/sdb1 /media
Newer Ubuntu distributions like Ubuntu 10.04 LTS natively supports NTFS partiitons, so in a Ubuntu server you can mount NTFS partition by just using the above mount commnad.