Dreadful tar with remote device

Adrian Wontroba aw1 at stade.co.uk
Wed Aug 16 04:46:57 BST 2000


On Sun, Aug 13, 2000 at 07:47:11PM +0000, Nik Clayton wrote:
> Diddle your tar blocksize.  I just tried similar experiments with a 
> 5MB file.

I agree.  I got some really startling differences in elapsed times with tar from
a notebook to a server (10MB file stats below).  The really optimum blocksizes form
quite a narrow band.  What is optimum for you is quite possibly very different.

Tue 28 Dec 1999 03:13:05 GMT
mervyn to titus blocksize 1
      508.48 real         0.14 user         0.43 sys

Tue 28 Dec 1999 03:21:33 GMT
mervyn to titus blocksize 2
      254.37 real         0.11 user         0.21 sys

Tue 28 Dec 1999 03:25:48 GMT
mervyn to titus blocksize 3
        5.24 real         0.02 user         0.19 sys

Tue 28 Dec 1999 03:25:53 GMT
mervyn to titus blocksize 4
        4.51 real         0.02 user         0.16 sys

Tue 28 Dec 1999 03:25:58 GMT
mervyn to titus blocksize 5
        4.05 real         0.03 user         0.11 sys

Tue 28 Dec 1999 03:26:02 GMT
mervyn to titus blocksize 6
        3.28 real         0.03 user         0.11 sys

Tue 28 Dec 1999 03:26:05 GMT
mervyn to titus blocksize 7
        3.14 real         0.00 user         0.13 sys

Tue 28 Dec 1999 03:26:08 GMT
mervyn to titus blocksize 8
        3.11 real         0.02 user         0.10 sys

Tue 28 Dec 1999 03:26:11 GMT
mervyn to titus blocksize 9
       56.71 real         0.03 user         0.10 sys

Tue 28 Dec 1999 03:27:08 GMT
mervyn to titus blocksize 10
       50.78 real         0.01 user         0.11 sys

Tue 28 Dec 1999 03:27:59 GMT
mervyn to titus blocksize 11
       45.98 real         0.00 user         0.13 sys

Tue 28 Dec 1999 03:28:45 GMT
mervyn to titus blocksize 12
        2.70 real         0.03 user         0.07 sys

Tue 28 Dec 1999 03:28:48 GMT
mervyn to titus blocksize 13
        3.39 real         0.00 user         0.10 sys

Tue 28 Dec 1999 03:28:51 GMT
mervyn to titus blocksize 14
        2.98 real         0.02 user         0.09 sys

Tue 28 Dec 1999 03:28:54 GMT
mervyn to titus blocksize 15
       33.84 real         0.08 user         0.08 sys

Tue 28 Dec 1999 03:29:28 GMT
mervyn to titus blocksize 16
       31.18 real         0.01 user         0.19 sys

Tue 28 Dec 1999 03:29:59 GMT
mervyn to titus blocksize 17
       29.78 real         0.00 user         0.08 sys

Tue 28 Dec 1999 03:30:29 GMT
mervyn to titus blocksize 18
       58.79 real         0.00 user         0.04 sys

Tue 28 Dec 1999 03:31:28 GMT
mervyn to titus blocksize 19
       49.01 real         0.00 user         0.08 sys

Tue 28 Dec 1999 03:32:17 GMT
mervyn to titus blocksize 20
       57.33 real         0.04 user         0.04 sys

Tue 28 Dec 1999 03:33:14 GMT
mervyn to titus blocksize 21
       54.78 real         0.00 user         0.08 sys

Tue 28 Dec 1999 03:34:09 GMT
mervyn to titus blocksize 22
       49.79 real         0.00 user         0.08 sys

Tue 28 Dec 1999 03:34:59 GMT
mervyn to titus blocksize 23
       43.50 real         0.00 user         0.08 sys

Tue 28 Dec 1999 03:35:42 GMT
mervyn to titus blocksize 24
       36.46 real         0.00 user         0.07 sys

Tue 28 Dec 1999 03:36:19 GMT
mervyn to titus blocksize 25
       39.49 real         0.00 user         0.08 sys

Tue 28 Dec 1999 03:36:58 GMT
mervyn to titus blocksize 26
       42.23 real         0.01 user         0.01 sys

Tue 28 Dec 1999 03:37:40 GMT
mervyn to titus blocksize 27
       45.22 real         0.01 user         0.00 sys

Tue 28 Dec 1999 03:38:26 GMT
mervyn to titus blocksize 28
       41.94 real         0.01 user         0.08 sys

Tue 28 Dec 1999 03:39:08 GMT
mervyn to titus blocksize 29
       31.12 real         0.00 user         0.06 sys

Tue 28 Dec 1999 03:39:39 GMT
mervyn to titus blocksize 30
       29.91 real         0.00 user         0.06 sys

Tue 28 Dec 1999 03:40:09 GMT
mervyn to titus blocksize 31
       28.96 real         0.00 user         0.07 sys

Tue 28 Dec 1999 03:40:38 GMT
mervyn to titus blocksize 32
       34.71 real         0.00 user         0.07 sys

Tue 28 Dec 1999 03:41:12 GMT
mervyn to titus blocksize 33
       32.61 real         0.00 user         0.07 sys

Tue 28 Dec 1999 03:41:45 GMT
mervyn to titus blocksize 34
       28.14 real         0.00 user         0.05 sys

Tue 28 Dec 1999 03:42:13 GMT
mervyn to titus blocksize 35
       22.29 real         0.00 user         0.06 sys

Tue 28 Dec 1999 03:42:36 GMT
mervyn to titus blocksize 36
       23.04 real         0.00 user         0.06 sys

Tue 28 Dec 1999 03:42:59 GMT
mervyn to titus blocksize 37
       20.09 real         0.00 user         0.05 sys

Tue 28 Dec 1999 03:43:19 GMT
mervyn to titus blocksize 38
       22.88 real         0.01 user         0.05 sys

Tue 28 Dec 1999 03:43:42 GMT
mervyn to titus blocksize 39
       26.04 real         0.00 user         0.07 sys

Tue 28 Dec 1999 03:44:08 GMT
mervyn to titus blocksize 40
       17.65 real         0.00 user         0.07 sys

-- 
Adrian Wontroba




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