xscsiha  - probe and control scsi buses accessed using the
       SGI linux-xscsi subsystem.


SYNOPSIS

       xscsiha [-lprtTws] [-D debuglevel] [-L targetID|all]
               [-S targetID|all] {{bus} ...


DESCRIPTION

       xscsiha is used  to  perform  operations  on  fibrechannel
       loops of SCSI devices and parallel SCSI buses.

       The  following  options  apply  to  both parallel SCSI and
       fibrechannel SCSI:

       -p     Probe for devices on the bus or loop.  On  parallel
              SCSI  buses,  this option causes the driver to look
              for devices at  every  ID  on  the  SCSI  bus.   On
              fibrechannel  SCSI  loops,  this  option causes the
              driver to look for devices at  every  ID  that  was
              reported in use at the most recent loop initializa­
              tion.  On parallel SCSI buses,  when  a  device  is
              found  at  lun  0,  all other luns are then probed.
              When devices or luns are not valid, a warning  mes­
              sage   may   be   printed  on  the  console.   With
              fibrechannel, the Report Luns SCSI command is  used
              to  determine  which LUNs are valid.  If the Report
              Luns command returns error, only LUN 0  is  assumed
              to be valid.

       -r     Perform a SCSI bus reset and/or reset host adapter.

              This affects all devices on that SCSI bus,  causing
              current  commands  to be aborted, and specially set
              parameters to be reset, in many cases.  Tape  drive
              state will be reset after this, and any tape opera­
              tions in progress will be aborted.

              This option should therefore be used with some cau­
              tion.  In very rare cases, it may cause a device to
              become unusable without a  powercycle.   There  are
              times  when  it  is  desired  to  reset  devices or
              adapters that appear to be hung, however,  so  this
              function  is  provided.   Some host adapter drivers
              will reset the  adapter  as  part  of  this  ioctl.
              Fibrechannel adapters will perform loop initializa­
              tion, making  this  operation  similar  to  the  -l
              option, except that the adapter will also be reset.

       -D debuglevel
              Set the debug level in  the  host  adapter  driver.
              Where  supported, this option changes the verbosity
              of a given host adapter driver.  In general,  0  is
              least verbose, with no specific upward limit.

       adapters:

       -t     Return interesting SCSI  bus  and  attached  target
              parameters.  Bus parameters include whether the bus
              is single-ended or differential, the SCSI  host  ID
              and  the  selection  timeout. The target parameters
              include whether the device is capable of  operating
              in  narrow  or  wide  mode, whether it's capable of
              doing synchronous transfer  and  if  so,  what  the
              period and offset is.

       The  following  options  only  apply  to Fibrechannel SCSI
       adapters:

       -l     Perform loop initialization.  During loop  initial­
              ization,  all  devices  on the loop will attempt to
              acquire a target ID.  SGI devices will  attempt  to
              get  the  ID they have been selected for, either by
              settings on and position within an enclosure, or by
              dials/switches  on the device.  If multiple devices
              have the same ID selection, only  one  device  will
              get that ID.  Other devices will attempt to acquire
              IDs not in already in use.

              This option may have a side effect of aborting cur­
              rent  commands  outstanding  on  the adapter, so it
              should be used with care.   The  disk  driver  will
              typically  reissue  the aborted commands, but there
              will be a performance  impact  while  commands  are
              reissued.

       -L targetID
              Send  LIPRST  to the specified device and then per­
              form loop initialization.  This option is much like
              -l  above,  except  that  it also requests that the
              device resets itself.  Not all devices  will  honor
              the  request.   RAID  controllers  typically  don't
              while disk drives typically do.  This option can be
              used  in rare cases where a device is not function­
              ing properly, but is still able  to  complete  loop
              initialization  and acquire a target ID.  For exam­
              ple, if a drive gets timeouts on attempts to  probe
              (using  the  -p option above), then this option may
              bring  it  back  to  working  condition.   In  this
              respect, the -L option can be used for reasons sim­
              ilar to -r on parallel SCSI buses.

       -L all This option is like the -L option  directly  above,
              except  that  it directs all devices to reset them­
              selves.  Only devices  that  implement  FC-AL-2  or
              later  will  respond  to  this.  This option can be
              used  if  a  loop  is  malfunctioning,  and  it  is

              the malfunction, but it isn't  known  which.   RAID
              controllers  typically don't honor the "self-reset"
              function of the LIPRST

              The -L options may have a side effect  of  aborting
              current commands outstanding on the adapter, and it
              if the device honors the reset function,  outstand­
              ing  commands  to  it  will  be  dropped.  The disk
              driver will typically reissue the aborted commands,
              but  there  will be a performance impact while com­
              mands are reissued and while a device resets.

       -T     Display a  listing  of  targets  connected  to  the
              fibrechannel adapter.

       -w     This  option  will  print  the  portname (sometimes
              known as the World Wide Name) of  the  fibrechannel
              adapter.

       -s     This option will print the link error statistics of
              the fibrechannel adapter.  The link  error  statis­
              tics  will  be  displayed  with  an  asterix before
              adapter loop id  (in  case  of  loop  topology)  or
              before  the  adapter  portname  (in  case of fabric
              topology).

       -S targetID
              This option will print the link error statistics of
              the  specified  fibrechannel target.  The target ID
              can be either unit number (in case of  loop  topol­
              ogy) or nodename (in case of fabric topology).

       -S all This option will print the link error statistics of
              the fibrechannel adapter and all the  targets  con­
              nected to it.


EXAMPLES

       To  reset a bus carrying a scsi adapter accessed under the
       SGI xscsi subsystem, use commands of the form:

       xxssccssiihhaa --rr //ddeevv//xxssccssii//ppccii0011..0088..00//bbuuss

       To probe the scsi bus , use commands of the form:

       xxssccssiihhaa --pp //ddeevv//xxssccssii//ppccii0011..0088..00//bbuuss


FILES

       /dev/xscsi/pci*/bus     the scsi bus operation devices


SEE ALSO

       xscsicontrol(8), xscsiadminswap(8), xscsiquiesce(8).

       This command is normally usable  only  by  the  superuser,
       because   the  standard  permissions  of  the  devices  in
       /dev/xscsi/* restrict access to other users.

       With Fibrechannel adapters, if a loop is  broken  after  a
       system  has  been  operational,  numerous attempts will be
       made to  reinitialize  the  loop,  after  which  the  host
       adapter  driver  will give up on the loop.  At this point,
       if the hardware condition causing the broken loop is fixed
       (box  of  drives powered back on, cable reinserted, etc.),
       the -r option should be used to re-establish  loop  opera­
       tion.


Man(1) output converted with man2html