Before you begin
- The base component and the FBA component of the DASD device driver
must have been compiled into the kernel or have been loaded as modules.
- The DASD device driver must have recognized the device as an FBA
device.
- You must know the device bus-ID or the device node through which
the DASD can be addressed. The DASD device nodes have the form /dev/dasd<x>,
where
<x> can be one to four
lowercase alphabetic characters.
Procedure
Perform these steps to prepare the DASD:
- 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 numbersThis table has two header rows. The
first two entries in the top row describe device names and minor numbers,
respectively, and span two columns each. The columns in the second
row always describe the first and last name or minor number of a range.
The fifth and last column has a single header and specifies the total
number of devices in the specified range. There are 5 data rows, 4
of which describe device ranges. The final data row has a single cell
with the total device count.
| 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 |
-
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).
-
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.
What to do next
To access FBA devices, use the DIAG access method.
