mirror of
git://sourceware.org/git/lvm2.git
synced 2024-12-21 13:34:40 +03:00
133 lines
2.8 KiB
Groff
133 lines
2.8 KiB
Groff
.TH DMSETUP 8 "Nov 29 2001" "Linux" "MAINTENTANCE COMMANDS"
|
|
.SH NAME
|
|
dmsetup \- low level logical volume management
|
|
.SH SYNOPSIS
|
|
.ad l
|
|
.B dmsetup create
|
|
.I device_name table_file
|
|
.br
|
|
.B dmsetup remove
|
|
.I device_name
|
|
.br
|
|
.B dmsetup suspend
|
|
.I device_name
|
|
.br
|
|
.B dmsetup resume
|
|
.I device_name
|
|
.br
|
|
.B dmsetup reload
|
|
.I device_name table_file
|
|
.br
|
|
.B dmsetup info
|
|
.I device_name
|
|
.ad b
|
|
.SH DESCRIPTION
|
|
dmsetup manages logical devices that use the device-mapper driver.
|
|
Devices are created by loading a table that specifies a target for
|
|
each sector in the logical device.
|
|
|
|
The first argument to dmsetup is a command.
|
|
The second argument is the logical device name.
|
|
.SH COMMANDS
|
|
.IP \fBcreate
|
|
.I device_name table_file
|
|
.br
|
|
Attempts to create a device using the table file given. If
|
|
successful a device will appear as
|
|
/dev/device-mapper/<device-name>. See below for information
|
|
on the table file format.
|
|
.IP \fBremove
|
|
.I device_name
|
|
.br
|
|
Removes the device
|
|
.IP \fBsuspend
|
|
.I device_name
|
|
.br
|
|
Suspends a device. Any I/O that has already been mapped by the device
|
|
but has not yet completed will be flushed. Any further I/O to that
|
|
device will be postponed for as long as the device is suspended.
|
|
.IP \fBresume
|
|
.I device_name
|
|
.br
|
|
Un-suspends a device. Postponed I/O now gets re-queued for processing.
|
|
.IP \fBreload
|
|
.I device_name table_file
|
|
.br
|
|
This command will only work if a device is in the suspended state.
|
|
It changes the mapping table for an existing device.
|
|
.IP \fBinfo
|
|
.I device_name
|
|
.br
|
|
Outputs some brief information about the device in the form:
|
|
.br
|
|
SUSPENDED|ACTIVE
|
|
.br
|
|
open_count
|
|
.br
|
|
major,minor
|
|
.br
|
|
target_count
|
|
.SH TABLE FORMAT
|
|
Each line of the table specifies a single target and is of the form:
|
|
.br
|
|
logical_start_sector num_sectors target_type target_args
|
|
.br
|
|
.br
|
|
At the moment there are 3 simple target types available - though your
|
|
system might have more in the form of modules.
|
|
|
|
.IP \fBlinear
|
|
.I destination_device start_sector
|
|
.br
|
|
The traditional linear mapping.
|
|
|
|
.IP \fBstriped
|
|
.I num_stripes chunk_size [destination start_sector]+
|
|
.br
|
|
Creates a striped area.
|
|
.br
|
|
e.g. striped 2 32 /dev/hda1 0 /dev/hdb1 0
|
|
will map the first chunk (16k) as follows:
|
|
.br
|
|
LV chunk 1 -> hda1, chunk 1
|
|
.br
|
|
LV chunk 2 -> hdb1, chunk 1
|
|
.br
|
|
LV chunk 3 -> hda1, chunk 2
|
|
.br
|
|
LV chunk 4 -> hdb1, chunk 2
|
|
.br
|
|
etc.
|
|
|
|
|
|
.IP \fBio-err
|
|
.br
|
|
Errors any I/O that goes to this area. Useful for testing or
|
|
for creating devices with holes in them.
|
|
|
|
|
|
.SH EXAMPLES
|
|
|
|
|
|
# A table to join two disks together
|
|
.br
|
|
.br
|
|
0 1028160 linear /dev/hda 0
|
|
.br
|
|
1028160 3903762 linear /dev/hdb 0
|
|
|
|
|
|
|
|
# A table to stripe across the two disks,
|
|
.br
|
|
# and add the spare space from
|
|
.br
|
|
# hdb to the back of the volume
|
|
|
|
0 2056320 striped 2 32 /dev/hda 0 /dev/hdb 0
|
|
.br
|
|
2056320 2875602 linear /dev/hdb 1028160
|
|
|
|
.SH AUTHORS
|
|
Original version: Joe Thornber (thornber@sistina.com)
|