Re: cpu usage for GTAR on alpha

[Uncle George]

224 min 'the program top' time. which is cpu time. the 78% to 90% ( with
it appearing every 5 secs ~82% in RN state, rather than in the expected
D ( disk activity ) state! ).

The program AMANDA, a backup system, would like to estimate disk usage.
it does this by running the backup program, in this case "tar", and
dumping all data to /dev/null. Amanda appears to expect that each drive
should take no longer that 5min to scan. 

"running: /bin/gtar: /bin/gtar --create --file /dev/null --directory /
--one-file-system --listed-incremental
/usr/local/var/amanda/gnutar-lists/mylaptop__0.new --sparse
--ignore-failed-read --totals . "

anyway, doing some further tests, i have used the 'time find .' command
to just go through the directories. for a file count of 443k, wall time
is some 47min, with 8sec user, 23sec system time.

I am now 'find'ing the whole drive, so i suspect that it will take some
80min wall time to complete.



Joerg Schilling wrote:
> 
> >From: Uncle George <address@hidden>
> 
> >i have a 160gig ide drive on my alpha. The drive is not terribly fast,
> >but apparently neither is the tar program that is going through the
> >992767 used inodes with 69gig disk space used.
> 
> >the program top shows that tar has used up some 224 minuts, thus far,
> >with some 60megs of main memory.  cpu usage seems to be  in the range of
> >77% to 90%. This is a 533mhz processor.
> 
> It is hard to tell what happened because your mail misses informaiton
> that would allow to judge....
> 
> 224 minutes real time?
> 224 minutes user cpu time?
> 224 minutes system cpu time?
> 
> Taking your numbers leads to an average file size of 73 kB which should
> give you more than 5 MB/s backup speed.
> 
> >Is there some reason why i am suffering so ?
> >Is there a remedy ( like an alternate sort algorithm ) ? for all the
> >files that i think you are storing in kore?
> 
> GNU tar is faster than many tar implementations used to be in the 1980s
> but from a today's view it is not optimized.
> 
> Did you try star?
> 
> ftp://ftp.fokus.gmd.de/pub/unix/star/alpha/
> 
> Note that if the time above is system time, things may have been caused
> by your OS. Just try star and compare.
> 
> Jörg
> 
>  EMail:address@hidden (home) Jörg Schilling D-13353 Berlin
>        address@hidden               (uni)  If you don't have iso-8859-1
>        address@hidden           (work) chars I am J"org Schilling
>  URL:  http://www.fokus.gmd.de/usr/schilling   ftp://ftp.fokus.gmd.de/pub/unix