add directory Minix

Minix/1.7.5/MANUALS/CAT1/VOL.1

@@ -0,0 +1,130 @@
+
+
+VOL(1)                    Minix Programmer's Manual                     VOL(1)
+
+
+NAME
+     vol - split input on or combine output from several volumes
+
+SYNOPSIS
+     vol [-rw1] [-b blocksize] [-m multiple] [size] device
+
+DESCRIPTION
+     Vol either reads a large input stream from standard input and distributes
+     it  over  several  volumes or combines volumes and sends them to standard
+     output.  The size of the  volumes  is  determined  automatically  if  the
+     device supports this, but may be specified before the argument naming the
+     device if automated detection is not possible or  if  only  part  of  the
+     physical  volume  is  used.   The  direction of the data is automatically
+     determined by checking whether the input or output of vol is  a  file  or
+     pipe.   Use  the  -r  or  -w  flag  if  you want to specify the direction
+     explicitly, in shell scripts for instance.
+
+     Vol waits for each new volume to be  inserted,  typing  return  makes  it
+     continue.  If no size is explicitely given then the size of the device is
+     determined each time before it is read or written, so it is  possible  to
+     mix  floppies  of  different  sizes.   If  the  size cannot be determined
+     (probably a tape) then the device is assumed to be infinitely  big.   Vol
+     can be used both for block or character devices.  It will buffer the data
+     and use a block size appropriate for fixed or variable block sized tapes.
+
+     Vol reads or writes  8192  bytes  to  block  devices,  usually  floppies.
+     Character  devices  are  read  or  written using a multiple of 512 bytes.
+     This multiple has an upper limit of 32767 bytes (16-bit machine),  64  kb
+     (32-bit),  or  even  1  Mb  (32-bit  VM).   The  last  partial write to a
+     character device is padded with zeros to the block size.  If a  character
+     device is a tape device that responds to the mtio(4) status call then the
+     reported tape block size will be used as the smallest unit.  If the  tape
+     is a variable block length device then it is read or written like a block
+     device, 8192 bytes at the time, with a minimum unit of one byte.
+
+     All sizes may be suffixed by the letters M, k, b or  w  to  multiply  the
+     number  by  mega,  kilo,  block  (512),  or word (2).  The volume size by
+     default in kilobytes if there is no suffix.
+
+OPTIONS
+
+     -rw  Explicitly specify reading or writing.  Almost mandatory in scripts.
+
+     -1   Just one volume, start immediately.
+
+     -b blocksize
+          Specify the device block size.
+
+     -m multiple
+          Specify the maximum read or write size of multiple blocks.   The  -b
+          and  -m  options allow one to modify the block size assumptions that
+          are made above.  These assumptions  are  -b  1  -m  8192  for  block
+          devices  or variable length tapes, and -b 512 -m 65536 for character
+          devices (32 bit machine.)  These options will not override the  tape
+          block  size  found  out  with  an mtio(4) call.  The multiple may be
+          larger then the default if vol can allocate the memory required.
+
+
+                                                                             1
+
+
+
+VOL(1)                    Minix Programmer's Manual                     VOL(1)
+
+
+EXAMPLES
+     To back up a tree to floppies as a compressed tarfile:
+
+          tar cf - . | compress | vol /dev/fd0
+
+     To restore a tree from 720 kb images from possibly bigger floppies:
+
+          vol 720 /dev/fd0 | uncompress | tar xfp -
+
+     Read or write a device with 1024 byte blocks:
+
+          vol -b 1k /dev/rsd15
+
+     Read or write a variable block length tape using blocking  factor  20  as
+     used by default by many tar(1) commands:
+
+          vol -m 20b /dev/rst5
+
+     Note that -m was used in the last example.  It sets the size  to  use  to
+     read  or  write,  -b  sets  the  basic  block size that may be written in
+     multiples.
+
+SEE ALSO
+     dd(1), tar(1), mt(1), mtio(4).
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+                                                                             2
+