rz(7) — Special Files
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
config_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?
config_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 number 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 (character) special file. Following the dsk is the logical device number (decimal) and then a letter, a through h, that represents the partition. Throughout this reference page, the question mark (?) character represents the logical device number in the name of the device special 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 buffer. 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
DiskStartLength
dsk?a040960
dsk?b40960122880
dsk?c0479350
dsk?d163840105170
dsk?e269010105170
dsk?f374180105170
dsk?g163840315510
dsk?h00
RZ25 Partitions
DiskStartLength
dsk?a0131072
dsk?b131072262144
dsk?c0832527
dsk?d393216146437
dsk?e539653146437
dsk?f686090146437
dsk?g393216439311
dsk?h00
RZ25L and RZ25M Partitions
DiskStartLength
dsk?a0131072
dsk?b131072262144
dsk?c01046206
dsk?d393216217663
dsk?e610879217663
dsk?f828542217664
dsk?g393216652990
dsk?h0 0
RZ26, RZ26L, and RZ26N Partitions
DiskStartLength
dsk?a0131072
dsk?b131072262144
dsk?c02050860
dsk?d393216552548
dsk?e945764552548
dsk?f1498312552548
dsk?g393216819200
dsk?h1212416838444
RZ28, RZ28B, RZ28L, RZ28M. and RZ1B∗ Partitions
sp
DiskStartLength
dsk?a0131072
dsk?b131072401408
dsk?c04110480
dsk?d5324801191936
dsk?e17244161191936
dsk?f29163521194128
dsk?g5324801787904
dsk?h23203841790096
RZ29, RZ29B, RZ29L, RZ29M and RZ1C∗ Partitions
DiskStartLength
dsk?a0131072
dsk?b131072401408
dsk?c08380080
dsk?d5324802623488
dsk?e31559682623488
dsk?f57794562600624
dsk?g5324803936256
dsk?h44687363911344
RZ55 Partitions
DiskStartLength
dsk?a0131072
dsk?b131072262144
dsk?c0649040
dsk?d00
dsk?e00
dsk?f00
dsk?g393216255824
dsk?h00
RZ56 Partitions
DiskStartLength
dsk?a0131072
dsk?b131072262144
dsk?c01299174
dsk?d393216301986
dsk?e695202301986
dsk?f997188301986
dsk?g393216819200
dsk?h121241686758
RZ58 Partitions
DiskStartLength
dsk?a0131072
dsk?b131072262144
dsk?c02698061
dsk?d393216768281
dsk?e1161497768282
dsk?f1929779768282
dsk?g393216819200
dsk?h12124161485645
RZ73 Partitions
DiskStartLength
dsk?a0131072
dsk?b131072262144
dsk?c03907911
dsk?d3932161171565
dsk?e15647811171565
dsk?f27363461171565
dsk?g393216819200
dsk?h12124162695495
RZ74 Partitions
DiskStartLength
dsk?a0131072
dsk?b131072393216
dsk?c06976375
dsk?d5242882150400
dsk?e26746882150400
dsk?f48250882151287
dsk?g5242883225600
dsk?h37498883226487
HSZ10, HSZ40, HSZ50, HSZ70 (RAID) Partitions
DiskStartLength
dsk?a0131072
dsk?b131072262144
dsk?c0end of media
dsk?d00
dsk?e00
dsk?f00
dsk?g393216 end of media
dsk?h00
RRD42, RRD43, RRD44, RRD45, and RRD46(Read-Only)
Partitions (CD-ROM)
DiskStartLength
dsk?a0(size varies per CD)
dsk?b00
dsk?c0(size varies per CD)
dsk?d00
dsk?e00
dsk?f00
dsk?g00
dsk?h00
RX23HD and RX26HD Partitions (High-Density)
DiskStartLength
dsk?a02880
dsk?b00
dsk?c02880
dsk?d00
dsk?e00
dsk?f00
dsk?g00
dsk?h00
RX23DD and RX26DD Partitions (Double-Density)
DiskStartLength
dsk?a01440
dsk?b00
dsk?c01440
dsk?d00
dsk?e00
dsk?f00
dsk?g00
dsk?h00
RX23SD and RX26SD Partitions (Single-Density)
DiskStartLength
dsk?a0720
dsk?b00
dsk?c0720
dsk?d00
dsk?e00
dsk?f00
dsk?g00
dsk?h00
RX26 Partitions (Extra-Density Floppy)
DiskStartLength
dsk?a05760
dsk?b00
dsk?c05760
dsk?d00
dsk?e00
dsk?f00
dsk?g00
dsk?h00
RX33 Partitions (Extra-Density)
DiskStartLength
dsk?a02400
dsk?b00
dsk?c02400
dsk?d00
dsk?e00
dsk?f00
dsk?g00
dsk?h00
RX33HD Partitions (High-Density)
DiskStartLength
dsk?a01440
dsk?b00
dsk?c01440
dsk?d00
dsk?e00
dsk?f00
dsk?g00
dsk?h00
RX33DD Partitions (Double-Density)
DiskStartLength
dsk?a0800
dsk?b00
dsk?c0800
dsk?d00
dsk?e00
dsk?f00
dsk?g00
dsk?h00
RX33SD Partitions (Single-Density)
DiskStartLength
dsk?a0720
dsk?b00
dsk?c0720
dsk?d00
dsk?e00
dsk?f00
dsk?g00
dsk?h00
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