Preparing an FBA-type DASD for use

Perform these steps to prepare the DASD:

1. Assure that device nodes exist to address the DASD as a whole and the partition.
   Example: To check if the device nodes for a DASD dasdzzy exist, change to /dev and issue:

   # ls dasdzzy*

   If necessary, create the device nodes. For example, issue:

   # mknod -m 660 /dev/dasdzzy b 94 73104
   # mknod -m 660 /dev/dasdzzy1 b 94 73105

   The following table shows the mapping of device names and minor numbers:

   Table 1. Mapping of DASD names to minor numbers

   Name for device as a whole		Minor number for device as a whole		Number of devices
   From	To	From	To
   dasda	dasdz	0	100	26
   dasdaa	dasdzz	104	2804	676
   dasdaaa	dasdzzz	2808	73108	17,576
   dasdaaaa	dasdnwtl	73112	1048572	243,866
   Total number of devices:				262,144

2. Depending on the intended use of the partition, create a file system on it or define it as a swap space.
   • Either create a file system of your choice, for example, with the Linux mke2fs command (see the man page for details).
     Example:

     # mke2fs -b 4096 /dev/dasdzzy1

   • Or define the partition as a swap space with the mkswap command (see the man page for details).
3. Mount the file system to the mount point of your choice in Linux or enable your swap partition.
   Tip: Mount file systems on FBA devices that are backed by z/VM® VDISKs with the discard mount option. This option frees memory when data is deleted from the device.
   Examples:

   • To mount a file system in a partition /dev/dasdzzy1, issue:

     # mount /dev/dasdzzy1 /mnt

   • To mount a VDISK-backed file system in a partition /dev/dasdzzx1, and use the discard option to free memory when data is deleted, issue:

     # mount -o discard /dev/dasdzzx1 /mnt