dasdfmt - formatting of DASD (ECKD) disk drives.
[-h] [-t] [-v] [-y] [-p] [-P] [-m step
] [-b blksize
] [-l volser
] [-d layout
[-L] [-V] [-F] [-k] [-C] [-M mode
formats a DASD (ECKD) disk drive to prepare it for usage with
Linux for S/390. The device
is the node of the device (e.g.
'/dev/dasda'). Any device node created by udev for kernel 2.6 can be used
: Careless usage of dasdfmt
can result in LOSS OF
- -h or --help
- Print usage and exit.
- -t or --test
- Disables any modification of the disk drive.
dasdfmt just prints out, what it would do.
- Increases verbosity.
- Start formatting without further user-confirmation.
- Remove permission for subsystem to format write record
This is an expert option: Per default in recent dasd drivers, subsystems are
granted the permission to format write record zero. This option is used to
remove this permission.
- -L or --no_label
- Omit the writing of a disk label after formatting.
This makes only sense for the 'ldl' disk layout.
The '-L' option has to be specified after the '-d ldl' option.
e.g. dasdfmt -d ldl -L /dev/...
- -V or --version
- Print version number and exit.
- -F or --force
- Formats the device without performing sanity checking.
- -C or --check_host_count
- Force dasdfmt to check the host access open count to ensure
the device is not online on another operating system instance
- -d layout or
- Formats the device with compatible disk layout or linux
disk layout. layout is either cdl for the compatible disk
layout (default) or ldl for the linux disk layout.
Compatible disk layout means a special handling of the first two tracks of
the volume. This enables other S/390 or zSeries operating systems to
access this device (e.g. for backup purposes).
- -p or --progressbar
- Print a progress bar while formatting. Do not use this
option if you are using a 3270 console, running in background or
redirecting the output to a file.
- -P or --percentage
- Print one line for each formatted cylinder showing the
number of the cylinder and percentage of formatting process. Intended to
be used by higher level interfaces.
- -m step or
- Print a hashmark every step cylinders. The value
step has to be within range [1,1000], otherwise it will be set to
the default, which is 10.
You can use this option to see the progress of formatting in case you are
not able to use the progress bar option -p, e.g. with a 3270 terminal.
The value will be at least as big as the -r or --requestsize value.
- -M mode or --mode=mode
- Specify the mode to be used to format the device.
Valid modes are:
- Format the entire disk with the specified blocksize.
- Format the first two tracks and write label and partition
information. Only use this option if you are sure that the target DASD
already contains a regular format with the specified blocksize. A
blocksize can optionally be specified using -b
- Format all unformatted tracks at the end of the target
DASD. This mode assumes that tracks at the beginning of the DASD volume
have already been correctly formatted, while a consecutive set of tracks
at the end are unformatted. You can use this mode to make added space
available for Linux use after dynamically increasing the size of a DASD
volume. A blocksize can optionally be specified using -b
- Perform a complete format check on a DASD volume. A
blocksize can be specified with -b (--blocksize).
- -r cylindercount or
- Number of cylinders to be processed in one formatting step.
The value must be an integer in the range 1 - 255.
Use this parameter to exploit any available PAV devices. The number of
cylinders optimally matches the number of associated devices, counting the
base device and all alias devices.
- -b blksize or
- Specify blocksize to be used. blksize must be a
positive integer and always be a power of two. The recommended blocksize
is 4096 bytes.
- -l volser or
- Specify the volume serial number or volume identifier to be
written to disk after formatting. If no label is specified, a sensible
default is used. volser is interpreted as ASCII string and is
automatically converted to uppercase and then to EBCDIC.
e.g. -l LNX001 or --label=DASD01
The volser identifies by serial number the volume. A volume serial
number is 1 through 6 alphanumeric or one of the following special
characters: $, #, @, %. Enclose a serial number that contains special
characters in apostrophes. If the number is shorter than six characters,
it is padded with trailing blanks.
Do not code a volume serial number as SCRTCH, PRIVAT, or Lnnnnn (L with five
numbers); these are used in OS/390 messages to ask the operator to mount a
volume. Do not code a volume serial number as MIGRAT, which is used by the
OS/390 Hierarchical Storage Manager DFSMShsm for migrated data sets.
NOTE: Try to avoid using special characters in the volume serial. This may
cause problems accessing a disk by volser.
In case you really have to use special characters, make sure you are using
quotes. In addition there is a special handling for the '$' sign. Please
specify it using '\$' if necessary.
e.g. -l 'a@b\$c#' to get A@B$C#
- -k or --keep_volser
- Keeps the Volume Serial Number, when writing the Volume
Label. This is useful, if the Serial Number has been written with a VM
Tool and should not be overwritten.