Provided by: blktool_4-7build1_amd64 
NAME
blktool - Display or change block device settings
SYNOPSIS
blktool [options] device [acoustic-mgmt nnn]
blktool [options] device [block-sz nnn]
blktool [options] device [bus-id]
blktool [options] device [bus-state nnn]
blktool [options] device [class]
blktool [options] device [cd-speed nnn]
blktool [options] device [defect-mgmt off|on]
blktool [options] device [dev-keep-settings off|on]
blktool [options] device [dev-read-ahead off|on]
blktool [options] device [dma off|on]
blktool [options] device [geometry]
blktool [options] device [i2o-rcache nnn]
blktool [options] device [i2o-wcache nnn]
blktool [options] device [id]
blktool [options] device [keep-settings off|on]
blktool [options] device [media unlock|lock]
blktool [options] device [multiple-count nnn]
blktool [options] device [no-write-err off|on]
blktool [options] device [pio-data 16-bit|32-bit]
blktool [options] device [pio-mode nnn]
blktool [options] device [pm-mode nnn]
blktool [options] device [queue-depth nnn]
blktool [options] device [read-ahead nnn]
blktool [options] device [readonly off|on]
blktool [options] device [reread-part]
blktool [options] device [reset]
blktool [options] device [sector-sz]
blktool [options] device [sleep]
blktool [options] device [standby]
blktool [options] device [unmask-irq off|on]
blktool [options] device [version]
blktool [options] [version]
blktool [options] device [wcache off|on]
DESCRIPTION
blktool is used for querying and/or changing settings of a block device.
device is the name of the block device to query or modify.
OPTIONS
-f For a few commands, blktool will flush the buffers of the block device out to disk, before
performing the requested command. Specify this option, "force", disables any flushing blktool
would attempt to do.
-t class
where class is one of 'ide', 'ata', 'scsi', 'i2o', or 'auto' to override the default auto-
detection of device class.
COMMANDS
acoustic-mgmt
Query or set underlying device's acoustic level.
block-sz
Query or set device block size.
bus-id Query device bus id.
bus-state
Query or set device bus state (0 off, 1 on, 2 tristate)
class Query the detected (or overridden, via -t) device class. Typically this will result in 'ATA' or
'SCSI' for most devices. Detection is based on device major; thus your SATA device may appear as
'SCSI'.
cd-speed
Set CD-ROM device speed (in Kbytes/sec).
defect-mgmt
Toggle underlying device's defect management (obsolete).
dev-keep-settings
Toggle underlying device's revert-to-defaults-on-reset feature.
dev-read-ahead
Toggle underlying device's read-ahead feature.
dma Toggle DMA data transfer. Omitting the on/off argument will print the current state.
geometry
Query device geometry (cylinders / heads / sectors / etc.).
i2o-rcache
Query or set an I2O block device's read cache.
i2o-wcache
Query or set an I2O block device's write cache.
id Query IDENTIFY [PACKET] DEVICE data.
keep-settings
Keep settings across device resets. Omitting the on/off argument will print the current state.
media Lock in (or unlock) a removable device.
multiple-count
Set multiple count for use in READ/WRITE MULTIPLE commands.
no-write-err
Toggle ignore-write-errors flag. Omitting the on/off argument will print the current state.
pio-data
ATA PIO data transfer via 16-bit or 32-bit I/O. Omitting the on/off argument will print the
current state.
pio-mode
Set underlying ATA device's PIO data transfer mode.
pm-mode
Set underlying device's Advanced Power Management mode.
queued-depth
Query or set underlying device's queue depth.
read-ahead
Query or set block device read-ahead (in units of sectors).
readonly
Toggle block device read-only setting. Omitting the on/off argument will print the current state.
reread-part
Re-read partition table.
reset Execute device reset.
sector-sz
Query device sector size.
sleep Put device to sleep immediately.
standby
Put device in standby mode.
unmask-irq
Toggle unmasked irqs. Omitting the on/off argument will print the current state.
version
Print version number and exit.
wcache Toggle underlying device's writeback cache.
BUGS
Inevitably there are some. Please report any you find.
AUTHOR
blktool was written by Jeff Garzik.
AVAILABILITY
blktool is available over the Web on the SourceForge site at http://sourceforge.net/projects/gkernel/