- Storage and SCSI tools
- User space tools
- Linux kernel drivers
The page is a resource for those looking for software tools for
storage devices with an emphasis on SCSI devices and Linux. These
tools are typically user space programs and most are listed under
that heading. There are also some Linux kernel drivers that may be
regarded as test tools, they are listed under a separate heading.
Here is another reference site that catalogs various manufacturer's
disk diagnostic utilities
User space tools
The entries below are brief abstracts with links to pages that have
more information. The entries are in alphabetical order.
This is a utility for fetching and changing parameters in the Linux
block subsystem. It supports ATA and SCSI disks with some support
for cd/dvd drives. Now maintained by Debian, see this site.
For finer grain control of SCSI devices (and SATA(PI) devices
connected via a SCSI to ATA Translation Layer (SATL)) see the sdparm utility below.
This is a disk exerciser that can do verification. It has an
dedup and compression aware pattern generation. See this site.
This utility is a variant of the standard Unix command dd which copies files. The ddpt utility specializes in
files that are block devices. For block devices that understand the
SCSI command set, finer grain control over the copy may be available
via a SCSI pass-through interface. Can also issue
SCSI XCOPY commands (both the older form from SPC-2 (now known as
"LID1") and a newer subset of LID4 known as ODX). It has been
developed for Linux and ported to FreeBSD, Solaris and Windows. See
This is a utility from Kurt Garloff <email@example.com>
for rescuing data from damaged media. It is a variant of dd that
will continue past errors on the input file. It is applicable to any
device that can be read by dd (e.g. IDE and SCSI disks, cd/dvds and
tapes). For more information see: www.garloff.de/kurt/linux/ddrescue
There is also a GNU program of the same name that has a similar
http://ftp.gnu.org/gnu/ddrescue/ . John Gilmour has some
information on disk recovery utilities at http://www.toad.com/gnu/sysadmin/
Devlabel is "a small user space app which maps symlinks to
underlying disk names. It uses [INQUIRY VPD] Page83/Page80 data to
track the true locations of disks even if their hd/sd name changes
and simply updates the symlink to point to the right place." Sysfs
support for the lk 2.6 series and support for multi-path
configurations is on the author's "to do" list. See http://www.lerhaupt.com/linux.html
. Probably better to use scsi_id/udev in the lk 2.6 series kernels
The Data Test (DT) program is modelled on dd's syntax but dt can
more than sequential copies. It is a comprehensive data test program
for SCSI devices such as disks, tapes and cdrom/dvds. It is
available on several Unix platforms (and NT), and its source is
available (unlike its stable mate scu discussed earlier).
See www.scsifaq.org/RMiller_Tools/index.html for
is written by Robin T. Miller <Robin.Miller at netapp dot com>
This utility tests the performance of Linux/Unix block devices or
file systems. fio is a tool that will
spawn a number of threads doing a particular type of IO action as specified by
the user in a defined job file.
fio supports various
types of IO backends, such as regular sync IO, linux aio, posix aio, and sg v3 IO (SG_IO
and queued read/write). fio
can be used for both performance testing, data/media verification, etc.
This utility gets and sets ATA drive parameters under Linux. Can
also get transport parameters for ATAPI devices. There is also
limited support for SCSI devices. See this site . Overlaps
in functionality with blktool (see above
). From hdparm version 7.0 onward, it can detect a SCSI to ATA
Translation Layer (SATL) allowing it to tunnel ATA commands.
This utility lists SCSI devices (or hosts) that have been detected
in a machine running a linux 2.6 series kernel. It is a passive
tools in the sense that it "data mines" the linux sysfs file system
rather than attempting to query devices. See lsscsi .
Michael Clark <firstname.lastname@example.org> describes his utility
thus: "mapscsi is a small utility that creates a consistent mapping
to Linux scsi devices. mapscsi achieves this by creating symbolic
links to linux scsi disk devices after scanning all scsi disk
devices, finding out their host, channel, id, lun, pci location (if
available), Fibre Channel world wide node and port names, loop and
port ids (with qla2x00 v4.46.5 driver) vendor, product and serial
number details and using this information plus a mapping rules file
containing device templates to dynamically create link names". For
more information see: http://gort.metaparadigm.com/mapscsi
. In the linux 2.6 series the scsi_id/udev pair is probably
Mark Harvey's Virtual Tape Library. See the mhvtl site.
This utility allows arbitrary SCSI commands to be sent to a device.
. It is similar to FreeBSD's camcontrol command. Recent versions of
the sg3_utils package include the
sg_raw utility which can also send arbitrary commands.
SAF-TE (SCSI Attached Fault-Tolerant Enclosure) is a SCSI command
set for monitoring and controlling enclosures and RAIDs. SAF-TE
devices report "processor" peripheral device type (0x3) in their
INQUIRY responses. More recent products tend to use SES (drafts at
http://www.t10.org ) which covers similar functionality. For a
SAF-TE monitoring tool for linux see: http://oss.metaparadigm.com/safte-monitor
This utility permits a user to add and remove scsi devices from the
Linux scsi subsystem on the fly. See scsiadd on this page .
Kurt Garloff <email@example.com> describes this utility thus:
"This program scans the SCSI bus and creates device nodes in
/dev/scsi/, which have a naming corresponding to their SCSI IDs and
LUNs, just like with devfs. (The devfs has no notion of host adapter
IDs, scsidev is better here.) Furthermore, the devices are inquired
to tell their names and serial numbers. Those can be compared with
the entries in a database /etc/scsi.alias and device nodes
corresponding to these entries are being built. So,this will even
work if you change the SCSI IDs of a device, where the devfs
approach would fail". For more information see: www.garloff.de/kurt/linux/scsidev
. He also has the useful rescan-scsi-bus.sh script at the
This utility is used by various linux 2.6 series distributions
together udev to dynamically add and remove scsi device nodes. See udev
's page. It also has a "man" page.
Older package that includes the scsiinfo
and scsiformat utilities
plus tcl/tk GUI interfaces for those utilities. The last update of
the scsiinfo package was in 1997. The function and syntax of the
scsiinfo utility have inspired sginfo
which now can be considered as a "drop in" replacement for scsiinfo
. Recent changes to SCSI standards (e.g. extra and extended mode
pages) are reflected in sginfo . In a similar way the sg_format utility can be thought
of as a modern replacement for the scsiformat utility. Both sginfo
and sg_format can be found in the sg3_utils
package. sdparm can do most of the
things that scsiinfo and sginfo can.
Steve Cameron <firstname.lastname@example.org> has the following
description at his site:
This is a utility to create and maintain symbolic links mapping a
predictable set of names to the rather unpredictable names used by
linux for disk devices. For example, you might map:
/dev/mydisk1 -> /dev/sda1
/dev/mydisk2 -> /dev/sdb1
/dev/mydisk3 -> /dev/sdc1
If you removed the disk corresponding to /dev/sdb1, then on
reboot, /dev/sdc1 will become /dev/sdb1, and /dev/sdc1 will be
gone. and your fstab will be wrong, etc. (Especially problematic
on a SAN). scsimap will maintain the mapping so that after
the reboot, /dev/mydisk3 -> will point to /dev/sdb1 and
/dev/mydisk2 will be gone. scsimap also handles later generation
Compaq array controllers (those which use the cciss driver.)
(scroll to the bottom of that page).
"This project includes changes that enhance the Reliability,
Availability and Serviceability (RAS) of the drivers that are
commonly used in a Linux software RAID-1 configuration. Other
efforts have been made to enable various common hardware RAID
adapters and their drivers on Linux." See http://scsirastools.sourceforge.net
. The package contains some low level scsi utilities including sgdskfl
to load disk firmware, sgmode to get and set mode pages, sgdefects
to read primary and grown defect lists and sgdiag to perform
format and other test functions.
The SCSI Command Utility (SCU) implements various SCSI commands
necessary for normal maintenance and diagnostics of SCSI
peripherals. Some of its features include: formatting, scanning for
(and reassigning) bad blocks, downloading new firmware, executing
diagnostics and obtaining performance information. It is available
on several Unix platforms (and NT), however it is only currently
available in binary form. See www.scsifaq.org/RMiller_Tools/index.html
for more details. scu is written by Robin T. Miller <Robin.Miller
at netapp dot com>
This utility allows information from SCSI mode pages to be fetched
and potentially modified. sdparm also
decodes Vital Product Data pages and can send simple SCSI command.
It was written for the Linux 2.4 and 2.6 series and has been ported
to FreeBSD, Solaris, Tru64 and Windows.
SeaTools is a freely available (binary, not source) utility for disk
diagnostics from Seagate which is a disk manufacturer. It can be
found at http://www.seagate.com
under the support tab. They have both a command line and a graphical
utility. Some of the facilities will work on any SCSI disks
while others are Seagate specific. Self tests, mode page settings
and formats (to different block sizes) are amongst the facilities
available. Other disk vendors have similar tools, see the reference
in the introduction section.
This is a package of utilities most of which send SCSI commands and
decode the response. This coverage
file contains a mapping of SCSI commands to utilities which send
those SCSI commands. The package also includes slightly higher level
utilities such as sg_dd which permit a finer level of control over
SCSI devices involved in copying compared to the standard Unix dd
command. sg3_utils is written for the
Linux 2.6 and 3 series and a large subset of its utilities have been
ported to FreeBSD, Solaris, Tru64 and Windows.
This package is the precursor of sg3_utils. sg_utils
was written for the Linux 2.2 series with some support for the linux
This package includes a command line utility, smartctl, and a daemon, smartd, to check the SMART
status and associated attributes of disks (both ATA and SCSI) and
tape drives. SMART is an acronym for Self-Monitoring, Analysis and
Reporting Technology. This project has taken over from smartsuite . See http://smartmontools.sourceforge.net
for more information. Recent versions have the ability to probe
(S)ATA disks behind SCSI transport infrastructure, specifically
behind a SCSI to ATA Translation Layer (SATL).
When things go wrong and smartmontools report problems then the Bad
Block Howto may be of use.
This is a package that supports S.M.A.R.T. capabilities built into
modern IDE and SCSI-3 disks. SMART is an acronym for
Self-Monitoring, Analysis and Reporting Technology. See sourceforge.net/projects/smartsuite
. This package is currently not actively maintained.
This is a package of utilities that sends Serial Attached SCSI (SAS)
Management Protocol (SMP) requests to a device (typically a SAS
expander) and decodes the response. See the smp_utils page.
This utility is used to measure I/O performance of character
devices, block devices, and regular files. It can also be used to
generate high I/O loads to stress systems while verifying data
integrity. It is easy to use and is flexible. No configuration files
or complicated client/server configurations are needed. Spew also
generates its own data patterns that are designed to make it easy to
find and debug data integrity problems. Mirrored on this location.
For those occasions when the master boot record is overwritten, testdisk can
find many different types of partitions and help with data recovery.
provides a dynamic device directory containing only the files for
actually present devices in linux 2.6 and 3 series kernels. It
creates or removes device node files usually located in the /dev
directory, or it renames network interfaces. For SCSI (and some ATA)
devices it has a helper called scsi_id which is described above.
This is a disk exerciser that can do verification. See this site.
The driver list below are often used when real SCSI or storage
devices are not available. Another use it to measure the Linux
kernel block and/or SCSI subsystem overhead.
A component of Mark Harvey's Virtual Tape Library is a Linux kernel
driver typically built as a module. It is derived from the
scsi_debug driver. See the mhvtl site.
null_blk is a Linux kernel driver typically built as a module. It is
a dummy block device with device names of the form /dev/nullb<n>
where <n> is a number starting at 0. Its overhead should be
much less than any real storage device and can be used for measuring
the block system overhead. Found in the Linux kernel series 3. Use
'modinfo null_blk' for information about its parameters.
scsi_debug is a Linux kernel driver typically built as a module. It
creates one or more dummy SCSI devices and also includes a dummy
SCSI host (HBA) which has a sysfs bus name of 'pseudo'. See the scsi_debug page.
Please contact the author with corrections or suggested additions to
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Last updated: 24th August 2014