I needed to copy some files from an old hard drive to a machine I have running CentOS 4, but the partition on the hard drive I needed to access was formatted with the reiserfs file system. The Linux kernel in CentOS 4 does not include support for reiserfs so you need to install a new kernel from the CentOS Plus repository. By doing this, the kernel is no longer the same as that provided by Red Hat’s Enterprise Linux, but you will be able to mount ReiserFS volumes.
If you try to mount a reiserfs filesystem but do not have support for reiserfs in the Linux kernel, you’ll get an error message like this:
mount: fs type reiserfs not supported by kernel
It’s possible to see what filesystems are supported by running this command:
cat /proc/filesystems
On my fairly default install CentOS 4 machine, the output of the above command was this:
nodev  sysfs nodev rootfs nodev bdev nodev proc nodev sockfs nodev binfmt_misc nodev usbfs nodev usbdevfs nodev futexfs nodev tmpfs nodev pipefs nodev eventpollfs nodev devpts ext2 nodev ramfs nodev hugetlbfs iso9660 nodev relayfs nodev mqueue ext3 nodev rpc_pipefs nodev autofs nodev nfs nodev nfs4
So clearly reiserfs was not available for mounting a filesyetem. To enable it, you need to edit the /etc/yum.repos.d/CentOS-Base.repo file and then install a special CentOS Plus kernel which includes reiserfs support. Using your favourite text editor (nano in the example below), run the following command to edit the file, running it either as the root user or using sudo:
nano /etc/yum.repos.d/CentOS-Base.repo
Look for the [centosplus] section and change the enabled flag from 0 to 1 and add the includepkgs line as shown below:
[centosplus] ... enabled=1 ... includepkgs=kernel* reiserfs-utils
Then add the following to the [base] and [updates] sections:
exclude=kernel kernel-devel kernel-smp-* kernel-hugemem* kernel-largesmp*
Now run the following command either as the root user or using sudo:
yum install reiserfs-utils kernel
This will do this:
Setting up Install Process Setting up repositories Reading repository metadata in from local files Excluding Packages from CentOS-4 - Updates Finished Excluding Packages from CentOS-4 - Base Finished Reducing CentOS-4 - Contrib to included packages only Finished Parsing package install arguments Resolving Dependencies --> Populating transaction set with selected packages. Please wait. ---> Package kernel.i686 0:2.6.9-67.0.1.EL.plus.c4 set to be installed ---> Package reiserfs-utils.i386 2:3.6.19-2.4.1 set to be updated --> Running transaction check Dependencies Resolved ============================================================================= Package Arch Version Repository Size ============================================================================= Installing: kernel i686 2.6.9-67.0.1.EL.plus.c4 centosplus 14 M reiserfs-utils i386 2:3.6.19-2.4.1 centosplus 434 k Transaction Summary ============================================================================= Install 2 Package(s) Update 0 Package(s) Remove 0 Package(s) Total download size: 15 M Is this ok [y/N]:
Type in “Y” and hit enter and then this will happen:
Downloading Packages: (1/2): reiserfs-utils-3.6 100% |=========================| 434 kB 00:04 (2/2): kernel-2.6.9-67.0. 100% |=========================| 14 MB 02:47 Running Transaction Test Finished Transaction Test Transaction Test Succeeded Running Transaction Installing: reiserfs-utils ######################### [1/2] Installing: kernel ######################### [2/2] Installed: kernel.i686 0:2.6.9-67.0.1.EL.plus.c4 reiserfs-utils.i386 2:3.6.19-2.4.1 Complete!
Once the installation has completed you need to reboot the system to load the new kernel and get access to the reiserfs partition.
After rebooting, cat /proc/filesystems will now show this:
nodev  sysfs nodev rootfs nodev bdev nodev proc nodev sockfs nodev binfmt_misc nodev usbfs nodev usbdevfs nodev futexfs nodev tmpfs nodev pipefs nodev eventpollfs nodev devpts ext2 nodev ramfs nodev hugetlbfs iso9660 nodev relayfs nodev mqueue ext3 nodev rpc_pipefs nodev autofs nodev nfs nodev nfs4 reiserfs
Note that reiserfs is now listed at the bottom, and you will be able to now successfully mount the filesystem formatted with reiserfs.
