

restor                       Command                       restor




Restore file system

rreessttoorr _c_o_m_m_a_n_d [_d_u_m_p__d_e_v_i_c_e][_f_i_l_e_s_y_s_t_e_m][_f_i_l_e ...]

restor copies  to the hard disk  one or more files  from tapes or
floppy disks written by the command dump.

command is a character from the set rRtxX, optionally modified by
v, f, or both.  The v  (verbose) modifier tells restor to print a
step-by-step trace  of its actions when  restoring an entire file
system.  This is for discovering  what went wrong when a mass re-
store runs into trouble.  The f modifier tells restor to take the
next argument as the path name of the dump device (tape or floppy
disk  drive).  If  the f  modifier is  not specified,  the device
/dev/dump is used.

The t command tells restor to read the header from the dump tape,
and display  the date  the dump tape  was written and  the ``dump
since'' date that produced the dump.

The x and X commands extract individual files from the dump tape.
Each argument is a file to  be extracted.  All file names are ab-
solute  path names  starting at  the root of  the dump  tape (the
first directory dumped, which is always the root directory of the
file system).  A numeric file name  is taken to be an i-number on
the dumped file system, permitting restore by i-number.

restor  looks up  each argument  file in  the directories  of the
dumped file system and prints out each name and associated i-num-
ber.  If  the command  is x, restor  extracts the files  from the
dump tape into files  in the current directory with names derived
from the  dumped file's i-number.  The X  command is similar, ex-
cept that before  it begins it asks the user  for the reel number
of the  dump tape, and continues asking for  dump reels until all
files have been extracted or the user types EOT.

The r and R commands allow  mass restoration of both full and in-
cremental  dump tapes  into the argument  file system.   The file
system must have enough data blocks and inodes to hold the dump.

The  mass restore  is performed  in three  phases.  In  the first
phase, restor  clears all i-nodes that were  either clear at dump
time  or are  going  to be  restored.  Any  allocated blocks  are
released.  Next,  it restores all files on  the tape.  The i-num-
bering is  preserved; however, data  blocks are allocated  in the
standard fashion.   Finally a pass  is made over  the i-nodes and
the list of free i-nodes in the superblock is updated.

The R  command is to  r as X is  to x: the r  command begins res-
toring immediately,  while the R  command pauses to  ask for reel
numbers.





COHERENT Lexicon                                           Page 1




restor                       Command                       restor



***** Files *****

/ddeevv/dduummpp -- Dump device
/eettcc/ddddaattee -- Dump date file

***** See Also *****

commands, dump, dumpdir

***** Diagnostics *****

Most of the  diagnostics produced by restor are self explanatory,
and are  caused by internal table overflows or  I/O errors on the
dump tape or file system.

If the dump spans multiple reels of tape, restor asks the user to
mount the  next reel  at the  appropriate time.  The  user should
type a  newline when the reel has  been mounted.  restor verifies
that this  is the correct reel and gives  the user another chance
if the reel number in the dump tape header is incorrect.

***** Notes *****

You cannot  perform a  mass restore  onto a live  root partition.
Instead, boot a  stand-alone version of COHERENT on a floppy-disk
drive,  or  boot  from an  alternative  COHERENT  file system  on
another hard-disk partition before  you attempt to do a mass res-
toration.

The handling  of tapes  with multiple  dumps on them  (created by
dumping  to the  no rewind  special files)  is not  very general.
Basically, restor  assumes that tapes holding  multiple dumps and
tapes  holding dumps  that span multiple  reels are  mutually ex-
clusive.  One can restore from  any file on a reel by positioning
the tape  and then restoring with  the x or r  commands, which do
not reposition the tape.  It  is (almost) impossible to use the X
or R commands, as the position of the dump tape will be lost when
restor closes it.



















COHERENT Lexicon                                           Page 2


