Content
Data
license:
Version: 9.51
Developer / Owner: Mark Lord
Short description:
The manual page and help for the hdparm linux command. Use this command to read or write parameters for SATA / IDE hard drives.
Man page output
man hdparmHDPARM(8) System Manager's Manual HDPARM(8)
NAME
hdparm - get/set SATA/IDE device parameters
SYNOPSIS
hdparm [options] [device ...]
DESCRIPTION
hdparm provides a command line interface to various kernel interfaces supported
by the Linux SATA/PATA/SAS "libata" subsystem and the older IDE driver subsys‐
tem. Many newer (2008 and later) USB drive enclosures now also support "SAT"
(SCSI-ATA Command Translation) and therefore may also work with hdparm. E.g.
recent WD "Passport" models and recent NexStar-3 enclosures. Some options may
work correctly only with the latest kernels.
OPTIONS
When no options are given, -acdgkmur is assumed. For "Get/set" options, a query
without the optional parameter (e.g. -d) will query (get) the device state, and
with a parameter (e.g., -d0) will set the device state.
-a Get/set sector count for filesystem (software) read-ahead. This is used
to improve performance in sequential reads of large files, by prefetching
additional blocks in anticipation of them being needed by the running
task. Many IDE drives also have a separate built-in read-ahead function,
which augments this filesystem (software) read-ahead function.
-A Get/set the IDE drive´s read-lookahead feature (usually ON by default).
Usage: -A0 (disable) or -A1 (enable).
-b Get/set bus state.
-B Get/set Advanced Power Management feature, if the drive supports it. A
low value means aggressive power management and a high value means better
performance. Possible settings range from values 1 through 127 (which
permit spin-down), and values 128 through 254 (which do not permit spin-
down). The highest degree of power management is attained with a setting
of 1, and the highest I/O performance with a setting of 254. A value of
255 tells hdparm to disable Advanced Power Management altogether on the
drive (not all drives support disabling it, but most do).
-c Get/set (E)IDE 32-bit I/O support. A numeric parameter can be used to
enable/disable 32-bit I/O support. Currently supported values include 0
to disable 32-bit I/O support, 1 to enable 32-bit data transfers, and 3
to enable 32-bit data transfers with a special sync sequence required by
many chipsets. The value 3 works with nearly all 32-bit IDE chipsets,
but incurs slightly more overhead. Note that "32-bit" refers to data
transfers across a PCI or VLB bus to the interface card only; all (E)IDE
drives still have only a 16-bit connection over the ribbon cable from the
interface card.
-C Check the current IDE power mode status, which will always be one of
unknown (drive does not support this command), active/idle (normal opera‐
tion), standby (low power mode, drive has spun down), or sleeping (lowest
power mode, drive is completely shut down). The -S, -y, -Y, and -Z
options can be used to manipulate the IDE power modes.
-d Get/set the "using_dma" flag for this drive. This option now works with
most combinations of drives and PCI interfaces which support DMA and
which are known to the kernel IDE driver. It is also a good idea to use
the appropriate -X option in combination with -d1 to ensure that the
drive itself is programmed for the correct DMA mode, although most BIOSs
should do this for you at boot time. Using DMA nearly always gives the
best performance, with fast I/O throughput and low CPU usage. But there
are at least a few configurations of chipsets and drives for which DMA
does not make much of a difference, or may even slow things down (on
really messed up hardware!). Your mileage may vary.
--dco-freeze
DCO stands for Device Configuration Overlay, a way for vendors to selec‐
tively disable certain features of a drive. The --dco-freeze option will
freeze/lock the current drive configuration, thereby preventing software
(or malware) from changing any DCO settings until after the next power-on
reset.
--dco-identify
Query and dump information regarding drive configuration settings which
can be disabled by the vendor or OEM installer. These settings show
capabilities of the drive which might be disabled by the vendor for
"enhanced compatibility". When disabled, they are otherwise hidden and
will not show in the -I identify output. For example, system vendors
sometimes disable 48_bit addressing on large drives, for compatibility
(and loss of capacity) with a specific BIOS. In such cases, --dco-iden‐
tify will show that the drive is 48_bit capable, but -I will not show it,
and nor will the drive accept 48_bit commands.
--dco-restore
Reset all drive settings, features, and accessible capacities back to
factory defaults and full capabilities. This command will fail if DCO is
frozen/locked, or if a -Np maximum size restriction has also been set.
This is EXTREMELY DANGEROUS and will very likely cause massive loss of
data. DO NOT USE THIS COMMAND.
--direct
Use the kernel´s "O_DIRECT" flag when performing a -t timing test. This
bypasses the page cache, causing the reads to go directly from the drive
into hdparm's buffers, using so-called "raw" I/O. In many cases, this
can produce results that appear much faster than the usual page cache
method, giving a better indication of raw device and driver performance.
--drq-hsm-error
VERY DANGEROUS, DON'T EVEN THINK ABOUT USING IT. This option causes
hdparm to issue an IDENTIFY command to the kernel, but incorrectly marked
as a "non-data" command. This results in the drive being left with its
DataReQust(DRQ) line "stuck" high. This confuses the kernel drivers, and
may crash the system immediately with massive data loss. The option
exists to help in testing and fortifying the kernel against similar real-
world drive malfunctions. VERY DANGEROUS, DO NOT USE!!
-D Enable/disable the on-drive defect management feature, whereby the drive
firmware tries to automatically manage defective sectors by relocating
them to "spare" sectors reserved by the factory for such. Control of
this feature via the -D option is not supported for most modern drives
since ATA-4; thus this command may fail.
-E Set cd/dvd drive speed. This is NOT necessary for regular operation, as
the drive will automatically switch speeds on its own. But if you want
to play with it, just supply a speed number after the option, usually a
number like 2 or 4. This can be useful in some cases, though, to smooth
out DVD video playback.
-f Sync and flush the buffer cache for the device on exit. This operation
is also performed internally as part of the -t and -T timings and other
options.
--fallocate
This option currently works only on ext4 and xfs filesystem types. When
used, this must be the only option given. It requires two parameters:
the desired file size in kilo-bytes (byte count divided by 1024), fol‐
lowed by the pathname for the new file. It will create a new file of the
specified size, but without actually having to write any data to the
file. This will normally complete very quickly, and without thrashing
the storage device.
E.g. Create a 10KByte file: hdparm --fallocate 10 temp_file
--fibmap
When used, this must be the only option given. It requires a file path
as a parameter, and will print out a list of the block extents (sector
ranges) occupied by that file on disk. Sector numbers are given as abso‐
lute LBA numbers, referenced from sector 0 of the physical device rather
than from the partition or filesystem. This information can then be used
for a variety of purposes, such as examining the degree of fragmenation
of larger files, or determining appropriate sectors to deliberately cor‐
rupt during fault-injection testing procedures.
This option uses the new FIEMAP (file extent map) ioctl() when available,
and falls back to the older FIBMAP (file block map) ioctl() otherwise.
Note that FIBMAP suffers from a 32-bit block-number interface, and thus
not work beyond 8TB or 16TB. FIBMAP is also very slow, and does not deal
well with preallocated uncommitted extents in ext4/xfs filesystems,
unless a sync() is done before using this option.
--fwdownload
When used, this should be the only option given. It requires a file path
immediately after the option, indicating where the new drive firmware
should be read from. The contents of this file will be sent to the drive
using the (S)ATA DOWNLOAD MICROCODE command, using either transfer proto‐
col 7 (entire file at once), or, if the drive supports it, transfer pro‐
tocol 3 (segmented download). This command is EXTREMELY DANGEROUS and
could destroy both the drive and all data on it. DO NOT USE THIS COM‐
MAND. The --fwdownload-mode3 , --fwdownload-mode3-max , and --fwdown‐
load-mode7 variations on basic --fwdownload allow overriding automatic
protocol detection in favour of forcing hdparm to use a specific transfer
protocol, for testing purposes only.
-F Flush the on-drive write cache buffer (older drives may not implement
this).
-g Display the drive geometry (cylinders, heads, sectors), the size (in sec‐
tors) of the device, and the starting offset (in sectors) of the device
from the beginning of the drive.
-h Display terse usage information (help).
-H Read the temperature from some (mostly Hitachi) drives. Also reports if
the temperature is within operating condition range (this may not be
reliable). Does not cause the drive to spin up if idle.
-i Display the identification info which the kernel drivers (IDE, libata)
have stored from boot/configuration time. This may differ from the cur‐
rent information obtainable directly from the drive itself with the -I
option. The data returned may or may not be current, depending on activ‐
ity since booting the system. For a more detailed interpretation of the
identification info, refer to AT Attachment Interface for Disk Drives,
ANSI ASC X3T9.2 working draft, revision 4a, April 19/93, and later edi‐
tions.
--idle-immediate
Issue an ATA IDLE_IMMEDIATE command, to put the drive into a lower power
state. Usually the device remains spun-up.
--idle-unload
Issue an ATA IDLE_IMMEDIATE_WITH_UNLOAD command, to unload or park the
heads and put the drive into a lower power state. Usually the device
remains spun-up.
-I Request identification info directly from the drive, which is displayed
in a new expanded format with considerably more detail than with the
older -i option.
--Istdin
This is a special variation on the -I option, which accepts a drive iden‐
tification block as standard input instead of using a /dev/hd* parameter.
The format of this block must be exactly the same as that found in the
/proc/ide/*/hd*/identify "files", or that produced by the --Istdout
option described below. This variation is designed for use with col‐
lected "libraries" of drive identification information, and can also be
used on ATAPI drives which may give media errors with the standard mecha‐
nism. When --Istdin is used, it must be the *only* parameter given.
--Istdout
This option dumps the drive's identify data in hex to stdout, in a format
similar to that from /proc/ide/*/identify, and suitable for later use
with the --Istdin option.
-J Get/set the Western Digital (WD) Green Drive's "idle3" timeout value.
This timeout controls how often the drive parks its heads and enters a
low power consumption state. The factory default is eight (8) seconds,
which is a very poor choice for use with Linux. Leaving it at the
default will result in hundreds of thousands of head load/unload cycles
in a very short period of time. The drive mechanism is only rated for
300,000 to 1,000,000 cycles, so leaving it at the default could result in
premature failure, not to mention the performance impact of the drive
often having to wake-up before doing routine I/O.
WD supply a WDIDLE3.EXE DOS utility for tweaking this setting, and you
should use that program instead of hdparm if at all possible. The
reverse-engineered implementation in hdparm is not as complete as the
original official program, even though it does seem to work on at a least
a few drives. A full power cycle is required for any change in setting
to take effect, regardless of which program is used to tweak things.
A setting of 30 seconds is recommended for Linux use. Permitted values
are from 8 to 12 seconds, and from 30 to 300 seconds in 30-second incre‐
ments. Specify a value of zero (0) to disable the WD idle3 timer com‐
pletely (NOT RECOMMENDED!).
-k Get/set the "keep_settings_over_reset" flag for the drive. When this
flag is set, the drive will preserve the -dmu settings over a soft reset,
(as done during the error recovery sequence). This option defaults to
off, to prevent drive reset loops which could be caused by combinations
of -dmu settings. The -k option should therefore only be set after one
has achieved confidence in correct system operation with a chosen set of
configuration settings. In practice, all that is typically necessary to
test a configuration (prior to using -k) is to verify that the drive can
be read/written, and that no error logs (kernel messages) are generated
in the process (look in /var/log/messages on most systems).
-K Set the drive´s "keep_features_over_reset" flag. Setting this enables
the drive to retain the settings for -APSWXZ over a soft reset (as done
during the error recovery sequence). Not all drives support this fea‐
ture.
-L Set the drive´s doorlock flag. Setting this to 1 will lock the door
mechanism of some removable hard drives (e.g. Syquest, ZIP, Jazz..), and
setting it to 0 will unlock the door mechanism. Normally, Linux main‐
tains the door locking mechanism automatically, depending on drive usage
(locked whenever a filesystem is mounted). But on system shutdown, this
can be a nuisance if the root partition is on a removable disk, since the
root partition is left mounted (read-only) after shutdown. So, by using
this command to unlock the door after the root filesystem is remounted
read-only, one can then remove the cartridge from the drive after shut‐
down.
-m Get/set sector count for multiple sector I/O on the drive. A setting of
0 disables this feature. Multiple sector mode (aka IDE Block Mode), is a
feature of most modern IDE hard drives, permitting the transfer of multi‐
ple sectors per I/O interrupt, rather than the usual one sector per
interrupt. When this feature is enabled, it typically reduces operating
system overhead for disk I/O by 30-50%. On many systems, it also pro‐
vides increased data throughput of anywhere from 5% to 50%. Some drives,
however (most notably the WD Caviar series), seem to run slower with mul‐
tiple mode enabled. Your mileage may vary. Most drives support the min‐
imum settings of 2, 4, 8, or 16 (sectors). Larger settings may also be
possible, depending on the drive. A setting of 16 or 32 seems optimal on
many systems. Western Digital recommends lower settings of 4 to 8 on
many of their drives, due tiny (32kB) drive buffers and non-optimized
buffering algorithms. The -i option can be used to find the maximum set‐
ting supported by an installed drive (look for MaxMultSect in the out‐
put). Some drives claim to support multiple mode, but lose data at some
settings. Under rare circumstances, such failures can result in massive
filesystem corruption.
--make-bad-sector
Deliberately create a bad sector (aka. "media error") on the disk.
EXCEPTIONALLY DANGEROUS. DO NOT USE THIS OPTION!! This can be useful for
testing of device/RAID error recovery mechanisms. The sector number is
given as a (base10) parameter after the option. Depending on the device,
hdparm will choose one of two possible ATA commands for corrupting the
sector. The WRITE_LONG works on most drives, but only up to the 28-bit
sector boundary. Some very recent drives (2008) may support the new
WRITE_UNCORRECTABLE_EXT command, which works for any LBA48 sector. If
available, hdparm will use that in preference to WRITE_LONG. The
WRITE_UNCORRECTABLE_EXT command itself presents a choice of how the new
bad sector should behave. By default, it will look like any other bad
sector, and the drive may take some time to retry and fail on subsequent
READs of the sector. However, if a single letter f is prepended immedi‐
ately in front of the first digit of the sector number parameter, then
hdparm will issue a "flagged" WRITE_UNCORRECTABLE_EXT, which causes the
drive to merely flag the sector as bad (rather than genuinely corrupt
it), and subsequent READs of the sector will fail immediately (rather
than after several retries). Note also that the --repair-sector option
can be used to restore (any) bad sectors when they are no longer needed,
including sectors that were genuinely bad (the drive will likely remap
those to a fresh area on the media).
-M Get/set Automatic Acoustic Management (AAM) setting. Most modern harddisk
drives have the ability to speed down the head movements to reduce their
noise output. The possible values are between 0 and 254. 128 is the most
quiet (and therefore slowest) setting and 254 the fastest (and loudest).
Some drives have only two levels (quiet / fast), while others may have
different levels between 128 and 254. At the moment, most drives only
support 3 options, off, quiet, and fast. These have been assigned the
values 0, 128, and 254 at present, respectively, but integer space has
been incorporated for future expansion, should this change.
-n Get or set the "ignore_write_errors" flag in the driver. Do NOT play
with this without grokking the driver source code first.
-N Get/set max visible number of sectors, also known as the Host Protected
Area setting. Without a parameter, -N displays the current setting,
which is reported as two values: the first gives the current max sectors
setting, and the second shows the native (real) hardware limit for the
disk. The difference between these two values indicates how many sectors
of the disk are currently hidden from the operating system, in the form
of a Host Protected Area (HPA). This area is often used by computer mak‐
ers to hold diagnostic software, and/or a copy of the originally provided
operating system for recovery purposes. Another possible use is to hide
the true capacity of a very large disk from a BIOS/system that cannot
normally cope with drives of that size (eg. most current {2010} BIOSs
cannot deal with drives larger than 2TB, so an HPA could be used to cause
a 3TB drive to report itself as a 2TB drive). To change the current max
(VERY DANGEROUS, DATA LOSS IS EXTREMELY LIKELY), a new value should be
provided (in base10) immediately following the -N option. This value is
specified as a count of sectors, rather than the "max sector address" of
the drive. Drives have the concept of a temporary (volatile) setting
which is lost on the next hardware reset, as well as a more permanent
(non-volatile) value which survives resets and power cycles. By default,
-N affects only the temporary (volatile) setting. To change the perma‐
nent (non-volatile) value, prepend a leading p character immediately
before the first digit of the value. Drives are supposed to allow only a
single permanent change per session. A hardware reset (or power cycle)
is required before another permanent -N operation can succeed. Note that
any attempt to set this value may fail if the disk is being accessed by
other software at the same time. This is because setting the value
requires a pair of back-to-back drive commands, but there is no way to
prevent some other command from being inserted between them by the ker‐
nel. So if it fails initially, just try again. Kernel support for -N is
buggy for many adapter types across many kernel versions, in that an
incorrect (too small) max size value is sometimes reported. As of the
2.6.27 kernel, this does finally seem to be working on most hardware.
--offset
Offsets to given number of GiB (1024*1024*1024) when performing -t tim‐
ings of device reads. Speed changes (about twice) along many mechanical
drives. Usually the maximum is at the beginning, but not always. Solid-
state drives (SSDs) should show similar timings regardless of offset.
-p Attempt to reprogram the IDE interface chipset for the specified PIO
mode, or attempt to auto-tune for the "best" PIO mode supported by the
drive. This feature is supported in the kernel for only a few "known"
chipsets, and even then the support is iffy at best. Some IDE chipsets
are unable to alter the PIO mode for a single drive, in which case this
option may cause the PIO mode for both drives to be set. Many IDE
chipsets support either fewer or more than the standard six (0 to 5) PIO
modes, so the exact speed setting that is actually implemented will vary
by chipset/driver sophistication. Use with extreme caution! This fea‐
ture includes zero protection for the unwary, and an unsuccessful outcome
may result in severe filesystem corruption!
-P Set the maximum sector count for the drive´s internal prefetch mechanism.
Not all drives support this feature, and it was dropped from the official
spec as of ATA-4.
--prefer-ata12
When using the SAT (SCSI ATA Translation) protocol, hdparm normally
prefers to use the 16-byte command format whenever possible. But some
USB drive enclosures don't work correctly with 16-byte commands. This
option can be used to force use of the smaller 12-byte command format
with such drives. hdparm will still revert to 16-byte commands for
things that cannot be done with the 12-byte format (e.g. sector accesses
beyond 28-bits).
-q Handle the next option quietly, suppressing normal output (but not error
messages). This is useful for reducing screen clutter when running from
system startup scripts. Not applicable to the -i or -v or -t or -T
options.
-Q Get or set the device's command queue_depth, if supported by the hard‐
ware. This only works with 2.6.xx (or later) kernels, and only with
device and driver combinations which support changing the queue_depth.
For SATA disks, this is the Native Command Queuing (NCQ) queue depth.
-r Get/set read-only flag for the device. When set, Linux disallows write
operations on the device.
-R Get/set Write-Read-Verify feature, if the drive supports it. Usage: -R0
(disable) or -R1 (enable). This feature is intended to have the drive
firmware automatically read-back any data that is written by software, to
verify that the data was successfully written. This is generally
overkill, and can slow down disk writes by as much as a factor of two (or
more).
--read-sector
Reads from the specified sector number, and dumps the contents in hex to
standard output. The sector number must be given (base10) after this
option. hdparm will issue a low-level read (completely bypassing the
usual block layer read/write mechanisms) for the specified sector. This
can be used to definitively check whether a given sector is bad (media
error) or not (doing so through the usual mechanisms can sometimes give
false positives).
--repair-sector
This is an alias for the --write-sector option. VERY DANGEROUS.
-s Enable/disable the power-on in standby feature, if supported by the
drive. VERY DANGEROUS. Do not use unless you are absolutely certain
that both the system BIOS (or firmware) and the operating system kernel
(Linux >= 2.6.22) support probing for drives that use this feature. When
enabled, the drive is powered-up in the standby mode to allow the con‐
troller to sequence the spin-up of devices, reducing the instantaneous
current draw burden when many drives share a power supply. Primarily for
use in large RAID setups. This feature is usually disabled and the drive
is powered-up in the active mode (see -C above). Note that a drive may
also allow enabling this feature by a jumper. Some SATA drives support
the control of this feature by pin 11 of the SATA power connector. In
these cases, this command may be unsupported or may have no effect.
-S Put the drive into idle (low-power) mode, and also set the standby (spin‐
down) timeout for the drive. This timeout value is used by the drive to
determine how long to wait (with no disk activity) before turning off the
spindle motor to save power. Under such circumstances, the drive may
take as long as 30 seconds to respond to a subsequent disk access, though
most drives are much quicker. The encoding of the timeout value is some‐
what peculiar. A value of zero means "timeouts are disabled": the device
will not automatically enter standby mode. Values from 1 to 240 specify
multiples of 5 seconds, yielding timeouts from 5 seconds to 20 minutes.
Values from 241 to 251 specify from 1 to 11 units of 30 minutes, yielding
timeouts from 30 minutes to 5.5 hours. A value of 252 signifies a time‐
out of 21 minutes. A value of 253 sets a vendor-defined timeout period
between 8 and 12 hours, and the value 254 is reserved. 255 is inter‐
preted as 21 minutes plus 15 seconds. Note that some older drives may
have very different interpretations of these values.
-t Perform timings of device reads for benchmark and comparison purposes.
For meaningful results, this operation should be repeated 2-3 times on an
otherwise inactive system (no other active processes) with at least a
couple of megabytes of free memory. This displays the speed of reading
through the buffer cache to the disk without any prior caching of data.
This measurement is an indication of how fast the drive can sustain
sequential data reads under Linux, without any filesystem overhead. To
ensure accurate measurements, the buffer cache is flushed during the pro‐
cessing of -t using the BLKFLSBUF ioctl.
-T Perform timings of cache reads for benchmark and comparison purposes.
For meaningful results, this operation should be repeated 2-3 times on an
otherwise inactive system (no other active processes) with at least a
couple of megabytes of free memory. This displays the speed of reading
directly from the Linux buffer cache without disk access. This measure‐
ment is essentially an indication of the throughput of the processor,
cache, and memory of the system under test.
--trim-sector-ranges
For Solid State Drives (SSDs). EXCEPTIONALLY DANGEROUS. DO NOT USE THIS
OPTION!! Tells the drive firmware to discard unneeded data sectors,
destroying any data that may have been present within them. This makes
those sectors available for immediate use by the firmware's garbage col‐
lection mechanism, to improve scheduling for wear-leveling of the flash
media. This option expects one or more sector range pairs immediately
after the option: an LBA starting address, a colon, and a sector count
(max 65535), with no intervening spaces. EXCEPTIONALLY DANGEROUS. DO NOT
USE THIS OPTION!!
E.g. hdparm --trim-sector-ranges 1000:4 7894:16 /dev/sdz
--trim-sector-ranges-stdin
Identical to --trim-sector-ranges above, except the list of lba:count
pairs is read from stdin rather than being specified on the command line.
This can be used to avoid problems with excessively long command lines.
It also permits batching of many more sector ranges into single commands
to the drive, up to the currently configured transfer limit (max_sec‐
tors_kb).
-u Get/set the interrupt-unmask flag for the drive. A setting of 1 permits
the driver to unmask other interrupts during processing of a disk inter‐
rupt, which greatly improves Linux´s responsiveness and eliminates
"serial port overrun" errors. Use this feature with caution: some
drive/controller combinations do not tolerate the increased I/O latencies
possible when this feature is enabled, resulting in massive filesystem
corruption. In particular, CMD-640B and RZ1000 (E)IDE interfaces can be
unreliable (due to a hardware flaw) when this option is used with kernel
versions earlier than 2.0.13. Disabling the IDE prefetch feature of
these interfaces (usually a BIOS/CMOS setting) provides a safe fix for
the problem for use with earlier kernels.
-v Display some basic settings, similar to -acdgkmur for IDE. This is also
the default behaviour when no options are specified.
-V Display program version and exit immediately.
--verbose
Display extra diagnostics from some commands.
-w Perform a device reset (DANGEROUS). Do NOT use this option. It exists
for unlikely situations where a reboot might otherwise be required to get
a confused drive back into a useable state.
--write-sector
Writes zeros to the specified sector number. VERY DANGEROUS. The sector
number must be given (base10) after this option. hdparm will issue a
low-level write (completely bypassing the usual block layer read/write
mechanisms) to the specified sector. This can be used to force a drive
to repair a bad sector (media error).
-W Get/set the IDE/SATA drive´s write-caching feature.
-X Set the IDE transfer mode for (E)IDE/ATA drives. This is typically used
in combination with -d1 when enabling DMA to/from a drive on a supported
interface chipset, where -X mdma2 is used to select multiword DMA mode2
transfers and -X sdma1 is used to select simple mode 1 DMA transfers.
With systems which support UltraDMA burst timings, -X udma2 is used to
select UltraDMA mode2 transfers (you´ll need to prepare the chipset for
UltraDMA beforehand). Apart from that, use of this option is seldom nec‐
essary since most/all modern IDE drives default to their fastest PIO
transfer mode at power-on. Fiddling with this can be both needless and
risky. On drives which support alternate transfer modes, -X can be used
to switch the mode of the drive only. Prior to changing the transfer
mode, the IDE interface should be jumpered or programmed (see -p option)
for the new mode setting to prevent loss and/or corruption of data. Use
this with extreme caution! For the PIO (Programmed Input/Output) trans‐
fer modes used by Linux, this value is simply the desired PIO mode number
plus 8. Thus, a value of 09 sets PIO mode1, 10 enables PIO mode2, and 11
selects PIO mode3. Setting 00 restores the drive´s "default" PIO mode,
and 01 disables IORDY. For multiword DMA, the value used is the desired
DMA mode number plus 32. for UltraDMA, the value is the desired UltraDMA
mode number plus 64.
-y Force an IDE drive to immediately enter the low power consumption standby
mode, usually causing it to spin down. The current power mode status can
be checked using the -C option.
-Y Force an IDE drive to immediately enter the lowest power consumption
sleep mode, causing it to shut down completely. A hard or soft reset is
required before the drive can be accessed again (the Linux IDE driver
will automatically handle issuing a reset if/when needed). The current
power mode status can be checked using the -C option.
-z Force a kernel re-read of the partition table of the specified device(s).
-Z Disable the automatic power-saving function of certain Seagate drives
(ST3xxx models?), to prevent them from idling/spinning-down at inconve‐
nient times.
ATA Security Feature Set
These switches are DANGEROUS to experiment with, and might not work with some
kernels. USE AT YOUR OWN RISK.
--security-help
Display terse usage info for all of the --security-* options.
--security-freeze
Freeze the drive´s security settings. The drive does not accept any
security commands until next power-on reset. Use this function in combi‐
nation with --security-unlock to protect drive from any attempt to set a
new password. Can be used standalone, too. No other options are permit‐
ted on the command line with this one.
--security-prompt-for-password
Prompt for the --security PWD rather than getting from the command line
args. This avoids having passwords show up in shell history or in
/proc/self/cmdline during execution.
--security-unlock PWD
Unlock the drive, using password PWD. Password is given as an ASCII
string and is padded with NULs to reach 32 bytes. The applicable drive
password is selected with the --user-master switch (default is "user"
password). No other options are permitted on the command line with this
one.
--security-set-pass PWD
Lock the drive, using password PWD (Set Password) (DANGEROUS). Password
is given as an ASCII string and is padded with NULs to reach 32 bytes.
Use the special password NULL to set an empty password. The applicable
drive password is selected with the --user-master switch (default is
"user" password) and the applicable security mode with the --security-
mode switch. No other options are permitted on the command line with
this one.
--security-disable PWD
Disable drive locking, using password PWD. Password is given as an ASCII
string and is padded with NULs to reach 32 bytes. The applicable drive
password is selected with the --user-master switch (default is "user"
password). No other options are permitted on the command line with this
one.
--security-erase PWD
Erase (locked) drive, using password PWD (DANGEROUS). Password is given
as an ASCII string and is padded with NULs to reach 32 bytes. Use the
special password NULL to represent an empty password. The applicable
drive password is selected with the --user-master switch (default is
"user" password). No other options are permitted on the command line
with this one.
--security-erase-enhanced PWD
Enhanced erase (locked) drive, using password PWD (DANGEROUS). Password
is given as an ASCII string and is padded with NULs to reach 32 bytes.
The applicable drive password is selected with the --user-master switch
(default is "user" password). No other options are permitted on the com‐
mand line with this one.
--user-master USER
Specifies which password (user/master) to select. Defaults to user pass‐
word. Only useful in combination with --security-unlock, --security-set-
pass, --security-disable, --security-erase or --security-erase-enhanced.
u user password
m master password
--security-mode MODE
Specifies which security mode (high/maximum) to set. Defaults to high.
Only useful in combination with --security-set-pass.
h high security
m maximum security
THIS FEATURE IS EXPERIMENTAL AND NOT WELL TESTED. USE AT YOUR OWN RISK.
FILES
/etc/hdparm.conf
BUGS
As noted above, the -m sectcount and -u 1 options should be used with caution at
first, preferably on a read-only filesystem. Most drives work well with these
features, but a few drive/controller combinations are not 100% compatible.
Filesystem corruption may result. Backup everything before experimenting!
Some options (e.g. -r for SCSI) may not work with old kernels as necessary
ioctl()´s were not supported.
Although this utility is intended primarily for use with SATA/IDE hard disk
devices, several of the options are also valid (and permitted) for use with SCSI
hard disk devices and MFM/RLL hard disks with XT interfaces.
The Linux kernel up until 2.6.12 (and probably later) doesn´t handle the secu‐
rity unlock and disable commands gracefully and will segfault and in some cases
even panic. The security commands however might indeed have been executed by the
drive. This poor kernel behaviour makes the PIO data security commands rather
useless at the moment.
Note that the "security erase" and "security disable" commands have been imple‐
mented as two consecutive PIO data commands and will not succeed on a locked
drive because the second command will not be issued after the segfault. See the
code for hints how patch it to work around this problem. Despite the segfault it
is often still possible to run two instances of hdparm consecutively and issue
the two necessary commands that way.
AUTHOR
hdparm has been written by Mark Lord <mlord@pobox.com>, the original primary
developer and maintainer of the (E)IDE driver for Linux, and current contributor
to the libata subsystem, along with suggestions and patches from many netfolk.
The disable Seagate auto-powersaving code is courtesy of Tomi Leppikan‐
gas(tomilepp@paju.oulu.fi).
Security freeze command by Benjamin Benz, 2005.
PIO data out security commands by Leonard den Ottolander, 2005. Some other
parts by Benjamin Benz and others.
SEE ALSO
http://www.t13.org/ Technical Committee T13 AT Attachment (ATA/ATAPI) Interface.
http://www.serialata.org/ Serial ATA International Organization.
http://www.compactflash.org/ CompactFlash Association.
Version 9.51 January 2017 HDPARM(8)
Help output
hdparm -hhdparm - get/set hard disk parameters - version v9.51, by Mark Lord. Usage: hdparm [options] [device ...] Options: -a Get/set fs readahead -A Get/set the drive look-ahead flag (0/1) -b Get/set bus state (0 == off, 1 == on, 2 == tristate) -B Set Advanced Power Management setting (1-255) -c Get/set IDE 32-bit IO setting -C Check drive power mode status -d Get/set using_dma flag -D Enable/disable drive defect management -E Set cd/dvd drive speed -f Flush buffer cache for device on exit -F Flush drive write cache -g Display drive geometry -h Display terse usage information -H Read temperature from drive (Hitachi only) -i Display drive identification -I Detailed/current information directly from drive -J Get/set Western DIgital "Idle3" timeout for a WDC "Green" drive (DANGEROUS) -k Get/set keep_settings_over_reset flag (0/1) -K Set drive keep_features_over_reset flag (0/1) -L Set drive doorlock (0/1) (removable harddisks only) -m Get/set multiple sector count -M Get/set acoustic management (0-254, 128: quiet, 254: fast) -n Get/set ignore-write-errors flag (0/1) -N Get/set max visible number of sectors (HPA) (VERY DANGEROUS) -p Set PIO mode on IDE interface chipset (0,1,2,3,4,...) -P Set drive prefetch count -q Change next setting quietly -Q Get/set DMA queue_depth (if supported) -r Get/set device readonly flag (DANGEROUS to set) -R Get/set device write-read-verify flag -s Set power-up in standby flag (0/1) (DANGEROUS) -S Set standby (spindown) timeout -t Perform device read timings -T Perform cache read timings -u Get/set unmaskirq flag (0/1) -U Obsolete -v Use defaults; same as -acdgkmur for IDE drives -V Display program version and exit immediately -w Perform device reset (DANGEROUS) -W Get/set drive write-caching flag (0/1) -x Obsolete -X Set IDE xfer mode (DANGEROUS) -y Put drive in standby mode -Y Put drive to sleep -z Re-read partition table -Z Disable Seagate auto-powersaving mode --dco-freeze Freeze/lock current device configuration until next power cycle --dco-identify Read/dump device configuration identify data --dco-restore Reset device configuration back to factory defaults --dco-setmax Use DCO to set maximum addressable sectors --direct Use O_DIRECT to bypass page cache for timings --drq-hsm-error Crash system with a "stuck DRQ" error (VERY DANGEROUS) --fallocate Create a file without writing data to disk --fibmap Show device extents (and fragmentation) for a file --fwdownload Download firmware file to drive (EXTREMELY DANGEROUS) --fwdownload-mode3 Download firmware using min-size segments (EXTREMELY DANGEROUS) --fwdownload-mode3-max Download firmware using max-size segments (EXTREMELY DANGEROUS) --fwdownload-mode7 Download firmware using a single segment (EXTREMELY DANGEROUS) --fwdownload-modee Download firmware using mode E (min-size segments) (EXTREMELY DANGEROUS) --fwdownload-modee-max Download firmware using mode E (max-size segments) (EXTREMELY DANGEROUS) --idle-immediate Idle drive immediately --idle-unload Idle immediately and unload heads --Istdin Read identify data from stdin as ASCII hex --Istdout Write identify data to stdout as ASCII hex --make-bad-sector Deliberately corrupt a sector directly on the media (VERY DANGEROUS) --offset use with -t, to begin timings at given offset (in GiB) from start of drive --prefer-ata12 Use 12-byte (instead of 16-byte) SAT commands when possible --read-sector Read and dump (in hex) a sector directly from the media --repair-sector Alias for the --write-sector option (VERY DANGEROUS) --sanitize-antifreeze-lock Block sanitize-freeze-lock command until next power cycle --sanitize-block-erase Start block erase operation --sanitize-crypto-scramble Change the internal encryption keys that used for used data --sanitize-freeze-lock Lock drive's sanitize features until next power cycle --sanitize-overwrite PATTERN Overwrite the internal media with constant PATTERN --sanitize-status Show sanitize status information --security-help Display help for ATA security commands --trim-sector-ranges Tell SSD firmware to discard unneeded data sectors: lba:count .. --trim-sector-ranges-stdin Same as above, but reads lba:count pairs from stdin --verbose Display extra diagnostics from some commands --write-sector Repair/overwrite a (possibly bad) sector directly on the media (VERY DANGEROUS)
Related Content
- 40 views