UniTree

UniTree
=======

The UniTree mass storage system is a UNIX-like environment that
is used at NCSA for all user data. UniTree manages the file system
by automatically migrating files off local disk space onto tape
when disk space becomes low or files have not been accessed in
a certain length of time. Files that have previously been migrated
to tape and purged off disk are automatically cached back to disk
when you request access. There are no UniTree quotas.

Access Methods

UniTree currently runs on a CONVEX C220 computer, which is accessed
using utility functions on NCSA's main systems or using standard
File Transfer Protocol (FTP). 

Access UniTree directly from the CM-5 by using either the mssftp
command, or the msscmd utility that utilizes mssftp. Descriptions
of these commands are available in man pages and in /usr/news/unitree
file. 

Access UniTree from other machines using FTP. UniTree's host machine
is named mss.ncsa.uiuc.edu. A password is required to use FTP
to access UniTree. For more information about your UniTree password,
refer to the packet from NCSA Allocations you received when your
account was established.

.trash Directory

UniTree differs from a standard UNIX file system by providing
a mechanism for recovery of accidentally deleted files. When a
file is deleted off UniTree, it is actually moved into a .trash
directory in your UniTree home directory. The file has a date
and time stamp appended when it is moved. The file then resides
in the .trash directory for n number of minutes, after which it
is permanently removed from the UniTree file system. You can determine
the current value of n by entering:

    ftp> quote site GTRSH 


Redundancy

The UniTree archival system offers you extra file protection when
archiving your files. You can specify that files stored into the
archival system be stored redundantly (i.e., multiple copies in
multiple places). 

Activate this feature within UniTree by entering:

    ftp> quote site NMDUP n


During an FTP session, all files stored after the command's execution
are stored n number of times. You can issue this command only
for new files being stored, and the command is valid only for
the current FTP session. The maximum redundancy available at NCSA
is two.

Help with UniTree

The User's Guide to the NCSA UniTree Archival System is available
online (see ``Online Resources'' on page 1 -- 7) or by contacting
orders@ncsa.uiuc.edu (see ``Printed Resources'' on page 1 -- 9).
Once in UniTree, the user guide is also available in the /DOCUMENTS
directory.

Contact the NCSA National Consulting Office (see ``Consulting
Office'' on page 1 -- 6) if you have any questions or experience
any problems in working with UniTree. 
.