ssd(7D) Devices ssd(7D)NAMEssd - 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 com‐
mand 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 usually
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 sys‐
tem. 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 accu‐
mulates 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 parti‐
tion 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 col‐
lected and makes these statistics unavail‐
able 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 property.
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.
physical-block-size SCSI Disk drivers take this value as the physi‐
cal block size of the disks which do not report
valid physical block size. The value must be a
power of two. If not specified, DEV_BSIZE(512
bytes) is implied.
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 set‐
ting
dn SCSI lun n
sn partition n (0-7)
SEE ALSOsar(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 5.10 17 May 2012 ssd(7D)
