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Date: Thu, 17 Aug 2000 02:28:12 -0700 (PDT)
From: jms@geriatrix.circlesquared.com
To: freebsd-gnats-submit@FreeBSD.org
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Subject: misc/20674: Dreadful tar performance with remote device
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>Number:         20674
>Category:       misc
>Synopsis:       Dreadful tar performance with remote device
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Thu Aug 17 02:30:00 PDT 2000
>Closed-Date:
>Last-Modified:
>Originator:     Jon Schneider
>Release:        4.1
>Organization:
>Environment:
(Not with me now but a cleanish 4.1-RELEASE)
>Description:
I initially noticed my established backup procedure was slow then found the
problem was that tar doesn't cope with remote devices very well even 
if they aren't remote. See how-to-repeat for output which shows that rsh/rcp
on its own is ok.

On a longer test the machine can be seen to be IDLE while it's taking
forever not transferring the data. This is why I think it is a bug
rather than overhead. I don't know whether it is tar or the kernel
waiting.

>How-To-Repeat:
Machine is a P233MMX...

Script started on Thu Aug 10 21:51:27 2000
bash-2.04# ls -l meg
-rw-r--r--  1 root  wheel  1048576 Aug 10 21:50 meg
bash-2.04# time rcp meg localhost:/tmp

real	0m0.374s
user	0m0.006s
sys	0m0.063s
bash-2.04# time tar cvf localhost:/tmp/fff.tar meg 
meg

real	0m10.511s
user	0m0.001s
sys	0m0.054s
bash-2.04# exit

Script done on Thu Aug 10 21:52:17 2000

The above is VERY sensitive to blocksize.
>Fix:


>Release-Note:
>Audit-Trail:
>Unformatted:


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