re man page on DigitalUNIX

Man page or keyword search:  
man Server   12896 pages
apropos Keyword Search (all sections)
Output format
DigitalUNIX logo
[printable version]

re(7)									 re(7)

       re - SWXCR RAID interface

       2100 Server Model A500MP DEC SWXCR controller xcrn at * vector xcintr

       device disk renn at xcrn drive nn

       The re driver is for the SWXCR RAID Array controller.

       The  following  rules are used to determine the major and minor numbers
       that are associated with an re type disk.  There are two major  numbers
       used to represent re disks.  The major numbers are 11 for block devices
       and 44 for character (raw) devices.

       The minor number is used to represent both the unit number  and	parti‐
       tion.   A disk partition refers to a designated portion of the physical
       disk.  To accomplish this reference, the 20-bit minor number is divided
       into  three  parts.   The lowest six bits of the minor number specify a
       disk partition.	The partitions use a letter, a through	h,  for	 their

       The  next three bits of the minor number specify the RE unit number for
       a unit attached to an SWXCR controller.	The final 11 bits specify  the
       controller number.

       The  device  special  file  names associated with re disks are based on
       conventions that are closely associated with the minor number  assigned
       to the disk.  The standard device names begin with re for block special
       files and rre for character (raw) special files. Following  the	re  is
       the  unit  number  and  then a letter, a through h, that represents the
       partition.  Throughout this reference page, the question mark (?) char‐
       acter  represents  the  unit  number  in the name of the device special
       file.  For example, re?b could represent re0b, re1b, and so on.

       The unit number can be calculated if the major and minor numbers of  an
       re  disk	 are provided.	For example, suppose you have a device special
       file rre6a, with a major number of 44 and a minor number of  384.   The
       partition  is  represented  by  the  lower  six bits of the number 384.
       These lower six bits of the number 384 are 0,  which  specifies	the  a
       partition.   The	 next  three  bits of the minor number 384 specify the
       unit number, which is 6. The next eleven bits  specify  the  controller
       number, which is zero. Putting these three pieces together reveals that
       the major/minor number pair 44/384 refers to the a partition of unit  6
       attached to controller number 0.

       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  capability  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

       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 RE 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 RE disks.

   Disk Support
       The RE driver handles all disk drives that  can	be  connected  to  the
       SWXCR controller.  To determine which drives are supported for specific
       CPU types and hardware configurations, see the Installation and Config‐
       uration Guide for the StorageWorks RAID Array 200 Subsystem Family.

       SWXCR  RAID Controllers are viewed in all cases as RE type disks. There
       are some notable 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 fixed sizes as  com‐
       pared to other disk devices.  The size of the Logical Volume is config‐
       urable 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 necessary, the disklabel(8)  command  can  be
       run to change and define partitions for RAID devices.

       Usually,	 the  re?a  partition is used for the root file system and the
       re?b partition as a paging area.	 The re?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 par‐
       titions of each drive are shown in the following table. Partition sizes
       can be changed by using the disklabel(8) command.

       SWXCR (RAID) partitions for systems based on the Alpha AXP architecture

	    disk start	   length

	    re?a 0    131072	   re?b 131072	  262144      re?c 0	end of
       media	       re?d 0	 0	     re?e 0    0	   re?f 0    0
	    re?g 393216	 end of media	   re?h 0    0




       disklabel(8), MAKEDEV(8), uerf(8)


List of man pages available for DigitalUNIX

Copyright (c) for man pages and the logo by the respective OS vendor.

For those who want to learn more, the polarhome community provides shell access and support.

[legal] [privacy] [GNU] [policy] [cookies] [netiquette] [sponsors] [FAQ]
Polarhome, production since 1999.
Member of Polarhome portal.
Based on Fawad Halim's script.
Vote for polarhome
Free Shell Accounts :: the biggest list on the net