fast mapcalc

Kenn Gardels (CEDR-REGIS) gardels at
Wed Jul 5 17:22:21 EDT 1995

> >
> >>OK smart fellas, show me!  Name four major commercial Unix systems with
> >>"ram-disk" and specifics about mounting procedures.

I just made a quick check on my DEC Alpha running OSF/1 3.0.  It apparently
supports a memory file system as well.  I've never used it, but now my 
curiousity is piqued - I'll give this a shot and see if I can do faster
process sequences.

Quoting from man page  

/usr/sbin/mfs [-F mount-flags] [newfs-options] [special-device] mount-node

  The mfs command builds a memory file system (mfs), which is a UFS file sys-
  tem in virtual memory, and mounts it on the specified mount-node.  When the
  file system is unmounted, mfs exits and the contents of the file system are
  lost.  If mfs is sent a signal while running, for example during system
  shutdown, it attempts to unmount its corresponding file system.  The param-
  eters for mfs are almost the same as those for newfs.  For a memory file
  system, the special-device file provides only a set of configuration param-
  eters, including the size of the virtual memory segment to allocate.  If
  the special-device file is omitted, you must specify the segment size.  The
  special-device file is usually the primary swap area, because that is where
  the file system is backed up when free memory gets low and the memory sup-
  porting the file system has to be paged.

  You can enable /tmp as a memory file system by adding an entry in the
  /etc/fstab file. For example, the following line creates a 10 Megabyte
  memory file system, mounted on /tmp:

       -s20480         /tmp   mfs rw 1 0

  Note that the contents of a memory file system are lost whenever a reboot
  or unmount is performed.

| Kenn Gardels                     Tel +01 (510) 642-9205                      |
| CEDR - 390 Wurster Hall          Fax +01 (510) 643-5571                      |
| University of California         Internet  gardels at          |
| Berkeley, CA  94720              Bitnet    gardels at UCBCED                    |


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