# phpman > man > scsi_readcap(8)

[SCSI_READCAP(8)](https://www.chedong.com/phpMan.php/man/SCSIREADCAP/8/markdown)                               SG3_UTILS                              [SCSI_READCAP(8)](https://www.chedong.com/phpMan.php/man/SCSIREADCAP/8/markdown)



## NAME
       scsi_readcap - do SCSI READ CAPACITY command on disks

## SYNOPSIS
       **scsi**___**readcap** [_--brief_] [_--help_] [_--long_] [_--verbose_] _DEVICE_ [_DEVICE_]*

## DESCRIPTION
       This  bash  shell  script calls the sg_readcap utility on each given _DEVICE_. This will send a
       SCSI READ CAPACITY command to each _DEVICE_.

       The default action of this script is to send the 10 byte cdb  READ  [CAPACITY(10)](https://www.chedong.com/phpMan.php/man/CAPACITY/10/markdown)  command  to
       each  _DEVICE_. If a response indicates the number of blocks is greater than or equal to '2**32
       - 1' then the READ [CAPACITY(16)](https://www.chedong.com/phpMan.php/man/CAPACITY/16/markdown) is sent and its response is output.

## OPTIONS
       Arguments to long options are mandatory for short options as well.

### -b --brief
              shortens the output to two hexadecimal numbers, both prefixed by '0x'.  The first num‐
              ber  is  the  number  of blocks available and the second is the size of each blocks in
              bytes (e.g. '0x12a19eb0 0x200'). If an error is detected '0x0 0x0' is output  and  the
              script continues if there are more _DEVICE_s.

### -h --help
              print out the usage message then exit.

### -l --long
              the  default  is to send the READ [CAPACITY(10)](https://www.chedong.com/phpMan.php/man/CAPACITY/10/markdown) command (i.e. the 10 byte cdb variant).
              When this option is given the READ [CAPACITY(16)](https://www.chedong.com/phpMan.php/man/CAPACITY/16/markdown) command is sent.  The  latter  command
              yields more information in its response.

### -v --verbose
              increase level or verbosity.

## EXIT STATUS
       The  exit status of this script is 0 when it is successful. Otherwise the exit status is that
       of the last sg_readcap utility called. See the [sg3_utils(8)](https://www.chedong.com/phpMan.php/man/sg3utils/8/markdown) man page.

## AUTHORS
       Written by D. Gilbert

## COPYRIGHT
       Copyright © 2009-2013 Douglas Gilbert
       This software is distributed under a FreeBSD license. There is NO warranty; not even for MER‐
       CHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

## SEE ALSO
       **sg**___**readcap** **(sg3**___**utils)**



sg3_utils-1.36                                May 2013                               [SCSI_READCAP(8)](https://www.chedong.com/phpMan.php/man/SCSIREADCAP/8/markdown)