Subject: mkisofs thrashing disk
To: None <tech-kern@netbsd.org>
From: David Laight <david@l8s.co.uk>
List: tech-kern
Date: 12/03/2002 15:45:36
I just make an archive of my netbsd $SRC tree using mkisofo and
writing the output to a file.
During the operation disk rattled like mad, doing continuous seeks.

Everything else got paged out rather badly...
I had vmstat -w1 running, at the end the numbers went:

 procs    memory      page                       disks         faults      cpu
 r b w    avm    fre  flt  re  pi po fr sr w0 c0 c1 f0   in   sy  cs us sy id
 0 1 0 170884    388  169 191   0  0 0 449 158 0  0  0  261  780 186  2  4 94
 0 1 0 170280    928  176 315   0  0 0 929 191 0  0  0  294 1011 229  2  2 96
 0 1 0 170012   1176  221 273   0  0 0 857 198 0  0  0  301 1000 239  1  7 92
 0 1 0 170524    624  101   0   1  0 0   0 122 0  0  0  224  691 153  0  4 96
 0 1 0 169900   1208   93 139   0  0 0 417 141 0  0  0  243  684 163  0  1 99
 0 1 0 170580    468  137   0   0  0 0   0 180 0  0  0  283  961 217  1  1 98
 0 0 0 116864  53928  178 267  15  3 0 835 169 0  0  0  271  913 231  1  5 94
 0 0 0 116864  53928   24   0   0  0 0   0 159 0  0  0  261  149  34  0  0 100
 0 0 0 116864  53928   12   0   0  0 0   0 148 0  0  0  250   97  19  0  1 99
 0 0 0 116864  53928   27   0   0  0 0   0 24  0  0  0  125  158  31  0  0 100
 0 0 0 116864  53928   12   0   0  0 0   0  0  0  0  0  101   89  17  0  0 100
 0 0 0 116864  53928   24   0   0  0 0   0  0  0  0  0  101  149  31  0  0 100

Note that when the program exited ~54000 (~220Mb) of memory suddenly
became free.  This can only have been the output file?  Which ought
to be a prime candidate for being written out.

Have I misinterpreted these statistics?

	David

-- 
David Laight: david@l8s.co.uk