ssd(7D) 							      Devices								   ssd(7D)

NAME

       ssd - Fibre Channel Arbitrated Loop disk device driver

SYNOPSIS

       ssd@port,target:partition

DESCRIPTION

	The ssd driver supports Fibre Channel disk devices.

       The  specific  type of each disk is determined by the SCSI inquiry command and reading the volume label stored on block 0 of the drive. The
       volume label describes the disk geometry and partitioning; it must be present or the disk cannot be mounted by the system.

       The block-files access the disk using the system's normal buffering mechanism and are read and written  without	regard	to  physical  disk
       records. A "raw" interface provides for direct transmission between the disk and the read or write buffer. A single read or write call usu-
       ally results in one I/O operation; raw I/O is therefore more efficient when many bytes are transmitted.	Block  file  names  are  found	in
       /dev/dsk; the names of the raw files are found in /dev/rdsk.

       I/O  requests (such as lseek(2)) to the SCSI disk must have an offset that is a multiple of 512 bytes (DEV_BSIZE), or the driver returns an
       EINVAL error. If the transfer length is not a multiple of 512 bytes, the transfer count is rounded up by the driver.

       Partition 0 is normally used for the root file system on a disk, with partition 1 as a paging area (for example, swap). Partition 2 is used
       to  back  up  the entire disk. Partition 2 normally maps the entire disk and may also be used as the mount point for secondary disks in the
       system. The rest of the disk is normally partition 6. For the primary disk, the user file system is located here.

       The device has associated error statistics. These must include counters for hard errors, soft errors and transport errors. Other  data  may
       be implemented as required.

DEVICE STATISTICS SUPPORT

       The  device  maintains  I/O  statistics for the device and for partitions allocated for that device. For each device/partition, the  driver
       accumulates reads, writes, bytes read, and bytes written. The driver also initiates hi-resolution time  stamps  at  queue  entry  and  exit
       points to enable monitoring of residence time and cumulative residence-length product for each queue.

       Not  all  device  drivers make per-partition IO statistics available for reporting. ssd and sd(7D) per-partition statistics are	enabled by
       default but may be disabled in their configuration files.

IOCTLS

       Refer to  dkio(7I).

ERRORS

       EACCES	 Permission denied.

       EBUSY	 The partition was opened exclusively by another thread.

       EFAULT	 The argument was a bad address.

       EINVAL	 Invalid argument.

       EIO	 An I/O error occurred.

       ENOTTY	 The device does not support the requested ioctl function.

       ENXIO	 When returned during  open(2), this error indicates the device does not exist.

       EROFS	 The device is a read-only device.

CONFIGURATION

       You configure the ssd driver by defining  properties in the ssd.conf file. The ssd driver supports the following properties:

       enable-partition-kstats	  The default value is 1, which causes partition IO statistics to be maintained. Set this value to zero to prevent
				  the  driver  from  recording	partition statistics. This slightly reduces the CPU overhead for IO, mimimizes the
				  amount of sar(1) data collected and makes these statistics unavailable for reporting by iostat(1M)  even  though
				  the -p/-P option is specified.  Regardless of this setting, disk IO statistics are always maintained.

       In  addition  to the above properties, some device-specific tunables can be configured in ssd.conf using the 'ssd-config-list' global prop-
       erty. The value of this property is a list of duplets. The formal syntax is:

	 ssd-config-list =   <duplet> [, <duplet> ]* ;

	 where

	 <duplet>:=	   "<vid+pid>" , "<tunable-list>"

	 and

	 <tunable-list>:=   <tunable>  [, <tunable> ]*;
	 <tunable> =	    <name> : <value>

	 The <vid+pid> is the string that is returned by the target device
	 on a SCSI inquiry command.

	 The <tunable-list> contains one or more tunables to apply to
	 all target devices with the specified <vid+pid>.

	 Each <tunable> is a <name> : <value> pair. Supported
	 tunable names are:

	    delay-busy: when busy, nsecs of delay before retry.

	    retries-timeout: retries to perform on an IO timeout.

EXAMPLES

	 The following is an example of a global ssd-config-list property:

	    ssd-config-list =
	       "SUN	T4", "delay-busy:600, retries-timeout:6",
	       "SUN	StorEdge_3510", "retries-timeout:3";

FILES

       ssd.conf 	     Driver configuration file

       /dev/dsk/cntndnsn     block files

       /dev/rdsk/cntndnsn    raw files

       cn		     is the controller number on the system.

       tn		     7-bit disk loop identifier, such as switch setting

       dn		     SCSI lun  n

       sn		     partition n (0-7)

SEE ALSO

       sar(1), format(1M), iostat(1M), ioctl(2), lseek(2), open(2), read(2), write(2), scsi(4)driver.conf(4), cdio(7I), dkio(7I)

       ANSI Small Computer System Interface-2 (SCSI-2)

       ANSI X3.272-1996, Fibre Channel Arbitrated Loop (FC-AL)

       Fibre Channel - Private Loop SCSI Direct Attach (FC-PLDA)

DIAGNOSTICS

	 Error for command '<command name>' Error Level: Fatal Requested Block <n>,
	 Error	Block: <m>, Sense Key: <sense key name>, Vendor '<vendor name>':
	 ASC = 0x<a> (<ASC name>), ASCQ = 0x<b>, FRU = 0x<c>

       The command indicated by <command name> failed. The Requested Block is the block where the transfer started and	the  Error  Block  is  the
       block that caused the error. Sense Key, ASC, and ASCQ information is returned by the target in response to a request sense command.

	 Check Condition on REQUEST SENSE

       A REQUEST SENSE command completed with a check condition. The original command will be retried a number of times.

	 Label says <m> blocks Drive says <n> blocks

       There is a discrepancy between the label and what the drive returned on the READ CAPACITY command.

	 Not enough sense information

       The request sense data was less than expected.

	 Request Sense couldn't get sense data

       The REQUEST SENSE command did not transfer any data.

	 Reservation Conflict

       The drive was reserved by another initiator.

	 SCSI transport failed: reason 'xxxx' : {retrying|giving up}

       The host adapter has failed to transport a command to the target for the  reason stated. The driver will either retry the command or, ulti-
       mately, give up.

	 Unhandled Sense Key <n>

       The REQUEST SENSE data included an invalid sense key.

	 Unit not Ready. Additional sense code 0x<n>

       The drive is not ready.

	 corrupt label - bad geometry

       The disk label is corrupted.

	 corrupt label - label checksum failed

       The disk label is corrupted.

	 corrupt label - wrong magic number

       The disk label is corrupted.

	 device busy too long

       The drive returned busy during a number of retries.

	 disk not responding to selection

       The drive was probably powered down or died.

	 i/o to invalid geometry

       The geometry of the drive could not be established.

	 incomplete read/write - retrying/giving up

       There was a residue after the command completed normally.

	 logical unit not ready

       The drive is not ready.

	 no bp for disk label

       A bp with consistent memory could not be allocated.

	 no mem for property

       Free memory pool exhausted.

	 no memory for disk label

       Free memory pool exhausted.

	 no resources for dumping

       A packet could not be allocated during dumping.

	 offline

       Drive went offline; probably powered down.

	 requeue of command fails<n>

       Driver attempted to retry a command and experienced a transport error.

	 ssdrestart transport failed <n>

       Driver attempted to retry a command and experienced a transport error.

	 transfer length not modulo <n>

       Illegal request size.

	 transport rejected <n>

       Host adapter driver was unable to accept a command.

	 unable to read label

       Failure to read disk label.

	 unit does not respond to selection

       Drive went offline; probably powered down.

SunOS 5.11							    9 Aug 2008								   ssd(7D)