s390-tools/dasdfmt/dasdfmt.8

.\" Copyright 2017 IBM Corp.
.\" s390-tools is free software; you can redistribute it and/or modify
.\" it under the terms of the MIT license. See LICENSE for details.
.\"
.TH DASDFMT 8 "Apr 2006" "s390-tools"
.SH NAME
dasdfmt \- formatting of DASD (ECKD) disk drives.

.SH SYNOPSIS
\fBdasdfmt\fR [\-h] [\-t] [\-v] [\-y] [\-p] [\-P] [\-m \fIstep\fR]
.br
        [\-r \fIcylinder\fR] [\-b \fIblksize\fR] [\-l \fIvolser\fR] [\-d \fIlayout\fR]
.br
        [\-L] [\-V] [\-F] [\-k] [\-C] [\-M \fImode\fR] \fIdevice\fR

.SH DESCRIPTION
\fBdasdfmt\fR formats a DASD (ECKD) disk drive to prepare it
for usage with Linux for S/390.
The \fIdevice\fR is the node of the device (e.g. '/dev/dasda').
Any device node created by udev for kernel 2.6 can be used
(e.g. '/dev/dasd/0.0.b100/disc').
.br

\fBWARNING\fR: Careless usage of \fBdasdfmt\fR can result in
\fBLOSS OF DATA\fR.

.SH OPTIONS
.TP
\fB\-h\fR or \fB\-\-help\fR
Print usage and exit.

.TP
\fB\-t\fR or \fB\-\-test\fR
Disables any modification of the disk drive.
.br
\fBdasdfmt\fR just prints
out, what it \fBwould\fR do.

.TP
\fB\-v\fR
Increases verbosity.

.TP
\fB\-y\fR
Start formatting without further user-confirmation.

.TP
\fB\-\-norecordzero\fR
Remove permission for subsystem to format write record zero.
.br
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.
.br

.TP
\fB\-L\fR or \fB\-\-no_label\fR
Omit the writing of a disk label after formatting.
.br
This makes only sense for the 'ldl' disk layout.
.br
The '\-L' option has to be specified after the '\-d ldl' option.
.br

e.g. dasdfmt \-d ldl \-L /dev/...


.TP
\fB\-V\fR or \fB\-\-version\fR
Print version number and exit.

.TP
\fB\-F\fR or \fB\-\-force\fR
Formats the device without performing sanity checking.

.TP
\fB\-C\fR or \fB\-\-check_host_count\fR
Force dasdfmt to check the host access open count to ensure the device
is not online on another operating system instance

.TP
\fB\-d\fR \fIlayout\fR or \fB\-\-disk_layout\fR=\fIlayout\fR
Formats the device with compatible disk layout or linux disk layout.
\fIlayout\fR is either \fIcdl\fR for the compatible disk layout
(default) or \fIldl\fR for the linux disk layout.
.br
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).

.TP
\fB-p\fR or \fB--progressbar\fR
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.

.TP
\fB\-P\fR or \fB\-\-percentage\fR
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.

.TP
\fB\-m\fR \fIstep\fR or \fB\-\-hashmarks\fR=\fIstep\fR
Print a hashmark every \fIstep\fR cylinders. The value \fIstep\fR has to be within range [1,1000], otherwise it will be set to the default, which is 10.
.br
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.
.br
The value will be at least as big as the \-r or \-\-requestsize value.
.br

.TP
\fB\-M\fR \fImode\fR or \fB\-\-mode\fR=\fImode\fR
Specify the \fImode\fR to be used to format the device. Valid modes are:
.RS
.IP full
Format the entire disk with the specified blocksize. (default)
.IP quick
Format the first two tracks and write label and partition information.
.br
Use this option for DASD ESE volumes to take the benefits of thin provisioning.
In this case, a full space release precedes the formatting step. If this space
release fails, then the formatting also fails. Specify the \fB\-\-no\-discard\fR
option to omit the space release.
.br
For non-ESE volumes use this option only if you are sure that the target DASD
already contains a regular format with the specified blocksize. A blocksize can
optionally be specified using \fB\-b\fR (\fB\-\-blocksize\fR).

.IP expand
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 \fB\-b\fR (\fB\-\-blocksize\fR).
.RE

.TP
\fB\-\-check\fR
Perform a complete format check on a DASD volume. A blocksize can be specified
with \fB\-b\fR (\fB\-\-blocksize\fR).

.TP
\fB\-\-no\-discard\fR
Omit a full space release when formatting a thin-provisioned DASD ESE volume.

.TP
\fB\-r\fR \fIcylindercount\fR or \fB\-\-requestsize\fR=\fIcylindercount\fR
Number of cylinders to be processed in one formatting step.
The value must be an integer in the range 1 - 255.
.br
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.
.br

.TP
\fB\-b\fR \fIblksize\fR or \fB\-\-blocksize\fR=\fIblksize\fR
Specify blocksize to be used. \fIblksize\fR must be a positive integer
and always be a power of two. The recommended blocksize is 4096 bytes.

.TP
\fB\-l\fR \fIvolser\fR or \fB\-\-label\fR=\fIvolser\fR
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. \fIvolser\fR is interpreted as ASCII string and is automatically
converted to uppercase and then to EBCDIC.
.br

e.g. \-l LNX001 or \-\-label=DASD01
.br

The \fIvolser\fR 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.
.br

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.
.br

NOTE: Try to avoid using special characters in the volume serial. This may cause problems accessing a disk by volser.
.br
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.
.br

e.g. \-l 'a@b\\$c#' to get A@B$C#
.br

.TP
\fB\-k\fR or \fB\-\-keep_volser\fR
Keeps the Volume Serial Number when writing the Volume Label. This is useful if
the volume already has a Serial Number that should not be overwritten.
.br

.SH SEE ALSO
.BR fdasd (8)