Installation guide

Section 2.4:Steps for Setting Up and Connecting the Cluster Hardware 53
# service rawdevices restart
Query all the raw devices by using the command raw -aq:
# raw -aq
/dev/raw/raw1 bound to major 8, minor 17
/dev/raw/raw2 bound to major 8, minor 18
Note that, for raw devices, there is no cache coherency between the raw device and the block device.
In addition, requests must be 512-byte aligned both in memory and on disk. For example, the standard
dd command cannot be used with raw devices because the memory buffer that the command passes
to the write system call is not aligned on a 512-byte boundary.
For more information on using the raw command, refer to the raw(8) manual page.
Creating File Systems
Use the mkfs command to create an ext2 file system on a partition. Specify the drive letter and the
partition number. For example:
# mkfs -t ext2 -b 4096 /dev/sde3
For optimal performance of shared filesystems, a 4 KB block size was specified in the above example.
Note that it is necessary in most cases to specify a 4 KB block size when creating a filesystem since
many of the mkfs file system build utilities default to a 1 KB block size, which can cause long fsck
times.
Similarly, to create an ext3 filesystem, the following command can be used:
# mkfs -t ext2 -j -b 4096 /dev/sde3
For more information on creating filesystems, refer to the mkfs(8) manual page.