Man page 5 : hdparm.conf

hdparm.conf - Debian configuration file for hdparm

This is the default configuration for hdparm for Debian. It is a rather simple script, so please follow the following guidelines :) Any line that begins with a comment is ignored - add as many as you like.

Note that an in-line comment is not supported. If a line consists of whitespace only (tabs, spaces, carriage return), it will be ignored, so you can space control fields as you like. ANYTHING ELSE IS PARSED!!

This means that lines with stray characters or lines that use non # comment characters will be interpreted by the initscript. This has probably minor, but potentially serious, side effects for your hard drives, so please follow the guidelines. Patches to improve flexibilty welcome.

Please read /usr/share/doc/hdparm/README.Debian for notes about known issues, especially if you have an MD array.

Note that if the init script causes boot problems, you can pass 'nohdparm' on the kernel command line, and the script will not be run.

Setting an option outside of one of the stanzas enables it for all drives.

If an option is listed twice, the second instance replaces the first.

/sbin/hdparm is not run unless a block of the form:

DEV {

• option
• option
• }

exists. This blocks will cause /sbin/hdparm OPTIONS DEV to be run. Where OPTIONS is the concatenation of all options previously defined outside of a block and all options defined with in the block.

• -q be quiet
      quiet
• -a sector count for filesystem read-ahead
      read_ahead_sect = 12
• -A disable/enable the IDE drive's read-lookahead feature
      lookahead = on
• -b bus state
      bus = on
• -B apm setting
      apm = 255
• -c enable (E)IDE 32-bit I/O support - can be any of 0,1,3
      io32_support = 1
• -d disable/enable the "using_dma" flag for this drive
      dma = off
• -D enable/disable the on-drive defect management
      defect_mana = off
• -E cdrom speed
      cd_speed = 16
• -k disable/enable the "keep_settings_over_reset" flag for this drive
      keep_settings_over_reset = off
• -K disable/enable the drive's "keep_features_over_reset" flag
      keep_features_over_reset = on
• -m sector count for multiple sector I/O
      mult_sect_io = 32
• -P maximum sector count for the drive's internal prefetch mechanism
      prefetch_sect = 12
• -r read-only flag for device
      read_only = off
• -s Enable/disable the power-on in standby feature
      poweron_standby = off
• -S standby (spindown) timeout for the drive
      spindown_time = 24
• -u interrupt-unmask flag for the drive
      interrupt_unmask = on
• -W Disable/enable the IDE drive's write-caching feature
      write_cache = off
• -X IDE transfer mode for newer (E)IDE/ATA2 drives
      transfer_mode = 34
• -y force to immediately enter the standby mode
      standby
• -Y force to immediately enter the sleep mode
      sleep
• -Z Disable the power-saving function of certain Seagate drives
      disable_seagate
• -M Set the acoustic management properties of a drive
      acoustic_management
• -p Set the chipset PIO mode
       chipset_pio_mode
• --security-freeze Freeze the drive's security status
      security_freeze
• --security-unlock Unlock the drive's security
      security_unlock = PWD
• --security-set-pass Set security password
      security_pass = password
• --security-disable Disable drive locking
      security_disable
• --user-master Specifies which password to select
      security_mode = u
• --security-mode Set the security mode
      security_mode = h
• Root file systems.
      Please see README.Debian for details. ROOTFS = /dev/hda

You can use straight hdparm commands in this config file as well - the set up is ugly, but it keeps backwards compatibility. Additionally, it should be noted that any blocks that begin with the keyword 'command_line' are not run until after the root filesystem is mounted. This is done to avoid running blocks twice. If you need to run hdparm to set parameters for your root disk, please use the standard format.

hdparm was written by Mark Lord <> The init script and configuration file are currently maintained by Stephen Gran <>, but are the result of the work of many people.

This manual page was created by Stephen Gran <> for the Debian GNU/Linux system (but may be used by others).