rz(7) Miscellaneous Information Manual rz(7)
NAME
rz - SCSI disk interface
SYNOPSIS
For each specific system, this information is located in the system configuration file in /sys/conf/<SYSTEM> and in /sys/conf/GENERIC.
AlphaServer 8200 and AlphaServer 8400 Qlogic ISP1020: bus tlsb0 at nexus? bus tiop0 at tlsb0 vector tioperror config_driver isp
AlphaServer 8200 and AlphaServer 8400 DEC KZMSA: bus tlsb0 at nexus? bus tiop0 at tlsb0 vector tioperror bus xmi0 at tiop? vector xmierror
config_driver xza DEC 7000/10000 DEC KZMSA: bus lsb0 at nexus? bus iop0 at lsb0 vector ioperror bus xmi0 at iop0 vector xmierror con-
fig_driver xza DEC 4000 DEC SIOP: bus ibus0 at nexus? bus lbus0 at ibus0 config_driver siop DEC 3000 NCR ASC: bus tc0 at nexus? con-
fig_driver tcds DEC 3000 DEC KZTSA: bus tc0 at nexus? config_driver tza DEC PCI bus DEC KZPSA: bus pci0 at * config_driver pza DEC PCI bus
NCR 810: bus pci0 at * config_driver psiop DEC PCI bus Qlogic ISP1020: bus pci0 at * config_driver isp DEC EISA bus Adaptec 1740: bus eisa0
at * config_driver aha
DESCRIPTION
The rz driver is for all Compaq Small Computer System Interface (SCSI) disk drives.
There is one major number used to represent SCSI disks, pointing to the driver. The minor number (for scsi) is the SCSI driver's logical ID
(or LID). This can be displayed with the following command: # scsimgr -sh all The minor number is used to represent both the SCSI unit num-
ber and partition. A disk partition refers to a designated portion of the physical disk. To accomplish this, the 20-bit minor number is
broken up into two parts. The low six bits of the minor number specify a disk partition. The partitions use a letter, a through h, as
their name. The next 14 bits of the minor number specify the SCSI unit number within a group of disks.
The device special file names associated with SCSI disks are based on conventions that are closely associated with the minor number
assigned to the disk. The standard device names begin with /dev/disk/dsk for the block special file and /dev/rdisk/dsk for the raw (char-
acter) special file. Following the dsk is the logical device number (decimal) and then a letter, a through h, that represents the parti-
tion. Throughout this reference page, the question mark (?) character represents the logical device number in the name of the device spe-
cial file. For example, dsk?b could represent dsk0b, or dsk1b.
A disk can be accessed through either the block special file or the character special file. The block special file accesses the disk using
the file system's normal buffering mechanism. Reads and writes to the block special file can specify any size. This avoids the need to
limit data transfers to the size of physical disk records and to calculate offsets within disk records. The file system can break up large
read and write requests into smaller fixed-size transfers to the disk.
The character special file provides a raw interface that allows for direct transmission between the disk and the user's read or write buf-
fer. A single read or write to the raw interface results in exactly one I/O operation. Consequently, raw I/O may be considerably more
efficient for large transfers.
For systems with SCSI disks, the first software boot after the system is powered on may take longer than expected. This delay is normal
and is caused by the software spinning up the SCSI disk drives.
Disk Support
This driver handles all disk drives that can be connected to the SCSI bus. Consult the Software Product Description (SPD) to determine
which drives are supported for which CPU types and hardware configurations.
SCSI RAID Controllers are viewed in most cases as SCSI-type disks. There are some differences that should be taken into consideration when
configuring a RAID device: Currently, only sector sizes of 512 bytes are supported. Logical Volume sizes are not a fixed size as compared
to other SCSI disk devices. The size of the Logical Volume is configurable based on needs. The DYNAMIC nature of Logical Volume sizes is
dealt with by defining RAID devices as DYNAMIC. Only partitions a, b, c, and g are defined. If needed, the disklabel(8) command can be
run to change and define partitions for RAID devices.
Usually, the dsk?a partition is used for the root file system and the dsk?b partition as a paging area. The dsk?c partition can be used
for disk-to-disk copying because it maps the entire disk.
The starting location and length (in 512-byte sectors) of the disk partitions of each drive are shown in the following tables. Partition
sizes can be changed by using the disklabel(8) command.
RZ24L Partitions
Disk Start Length
dsk?a 0 40960
dsk?b 40960 122880
dsk?c 0 479350
dsk?d 163840 105170
dsk?e 269010 105170
dsk?f 374180 105170
dsk?g 163840 315510
dsk?h 0 0
RZ25 Partitions
Disk Start Length
dsk?a 0 131072
dsk?b 131072 262144
dsk?c 0 832527
dsk?d 393216 146437
dsk?e 539653 146437
dsk?f 686090 146437
dsk?g 393216 439311
dsk?h 0 0
RZ25L and RZ25M Partitions
Disk Start Length
dsk?a 0 131072
dsk?b 131072 262144
dsk?c 0 1046206
dsk?d 393216 217663
dsk?e 610879 217663
dsk?f 828542 217664
dsk?g 393216 652990
dsk?h 0 0
RZ26, RZ26L, and RZ26N Partitions
Disk Start Length
dsk?a 0 131072
dsk?b 131072 262144
dsk?c 0 2050860
dsk?d 393216 552548
dsk?e 945764 552548
dsk?f 1498312 552548
dsk?g 393216 819200
dsk?h 1212416 838444
RZ28, RZ28B, RZ28L, RZ28M. and RZ1B* Partitions
sp
Disk Start Length
dsk?a 0 131072
dsk?b 131072 401408
dsk?c 0 4110480
dsk?d 532480 1191936
dsk?e 1724416 1191936
dsk?f 2916352 1194128
dsk?g 532480 1787904
dsk?h 2320384 1790096
RZ29, RZ29B, RZ29L, RZ29M and RZ1C* Partitions
Disk Start Length
dsk?a 0 131072
dsk?b 131072 401408
dsk?c 0 8380080
dsk?d 532480 2623488
dsk?e 3155968 2623488
dsk?f 5779456 2600624
dsk?g 532480 3936256
dsk?h 4468736 3911344
RZ55 Partitions
Disk Start Length
dsk?a 0 131072
dsk?b 131072 262144
dsk?c 0 649040
dsk?d 0 0
dsk?e 0 0
dsk?f 0 0
dsk?g 393216 255824
dsk?h 0 0
RZ56 Partitions
Disk Start Length
dsk?a 0 131072
dsk?b 131072 262144
dsk?c 0 1299174
dsk?d 393216 301986
dsk?e 695202 301986
dsk?f 997188 301986
dsk?g 393216 819200
dsk?h 1212416 86758
RZ58 Partitions
Disk Start Length
dsk?a 0 131072
dsk?b 131072 262144
dsk?c 0 2698061
dsk?d 393216 768281
dsk?e 1161497 768282
dsk?f 1929779 768282
dsk?g 393216 819200
dsk?h 1212416 1485645
RZ73 Partitions
Disk Start Length
dsk?a 0 131072
dsk?b 131072 262144
dsk?c 0 3907911
dsk?d 393216 1171565
dsk?e 1564781 1171565
dsk?f 2736346 1171565
dsk?g 393216 819200
dsk?h 1212416 2695495
RZ74 Partitions
Disk Start Length
dsk?a 0 131072
dsk?b 131072 393216
dsk?c 0 6976375
dsk?d 524288 2150400
dsk?e 2674688 2150400
dsk?f 4825088 2151287
dsk?g 524288 3225600
dsk?h 3749888 3226487
HSZ10, HSZ40, HSZ50, HSZ70 (RAID) Partitions
Disk Start Length
dsk?a 0 131072
dsk?b 131072 262144
dsk?c 0 end of media
dsk?d 0 0
dsk?e 0 0
dsk?f 0 0
dsk?g 393216 end of media
dsk?h 0 0
RRD42, RRD43, RRD44, RRD45, and RRD46(Read-Only)
Partitions (CD-ROM)
Disk Start Length
dsk?a 0 (size varies per CD)
dsk?b 0 0
dsk?c 0 (size varies per CD)
dsk?d 0 0
dsk?e 0 0
dsk?f 0 0
dsk?g 0 0
dsk?h 0 0
RX23HD and RX26HD Partitions (High-Density)
Disk Start Length
dsk?a 0 2880
dsk?b 0 0
dsk?c 0 2880
dsk?d 0 0
dsk?e 0 0
dsk?f 0 0
dsk?g 0 0
dsk?h 0 0
RX23DD and RX26DD Partitions (Double-Density)
Disk Start Length
dsk?a 0 1440
dsk?b 0 0
dsk?c 0 1440
dsk?d 0 0
dsk?e 0 0
dsk?f 0 0
dsk?g 0 0
dsk?h 0 0
RX23SD and RX26SD Partitions (Single-Density)
Disk Start Length
dsk?a 0 720
dsk?b 0 0
dsk?c 0 720
dsk?d 0 0
dsk?e 0 0
dsk?f 0 0
dsk?g 0 0
dsk?h 0 0
RX26 Partitions (Extra-Density Floppy)
Disk Start Length
dsk?a 0 5760
dsk?b 0 0
dsk?c 0 5760
dsk?d 0 0
dsk?e 0 0
dsk?f 0 0
dsk?g 0 0
dsk?h 0 0
RX33 Partitions (Extra-Density)
Disk Start Length
dsk?a 0 2400
dsk?b 0 0
dsk?c 0 2400
dsk?d 0 0
dsk?e 0 0
dsk?f 0 0
dsk?g 0 0
dsk?h 0 0
RX33HD Partitions (High-Density)
Disk Start Length
dsk?a 0 1440
dsk?b 0 0
dsk?c 0 1440
dsk?d 0 0
dsk?e 0 0
dsk?f 0 0
dsk?g 0 0
dsk?h 0 0
RX33DD Partitions (Double-Density)
Disk Start Length
dsk?a 0 800
dsk?b 0 0
dsk?c 0 800
dsk?d 0 0
dsk?e 0 0
dsk?f 0 0
dsk?g 0 0
dsk?h 0 0
RX33SD Partitions (Single-Density)
Disk Start Length
dsk?a 0 720
dsk?b 0 0
dsk?c 0 720
dsk?d 0 0
dsk?e 0 0
dsk?f 0 0
dsk?g 0 0
dsk?h 0 0
EXAMPLES
The following example shows the configuration specification that you might have for a DEC 3000 Model 500 system with a PMAZC controller in
slot 0 and KZTSA devices in slots 1 and 2: bus tc0 at nexus? config_driver tcds config_driver tza
The following system contains an NCR 810 controller for attaching CD-ROMS, KZPSA adapters for shared storage cluster connectivity, and
KZPBA (qlogic) adapters: bus pci0 at * config_driver psiop config_driver pza config_driver isp
FILES
/dev/disk/dsk??
/dev/rdisk/dsk??
/etc/disktab
/sys/conf/SYSTEM
RELATED INFORMATION
RAID(7), SCSI(7), tz(7), disklabel(8), MAKEDEV(8), uerf(8) delim off
rz(7)