Re: [AVFS] Speed suddenly decreases after copying 100 MB of data

Ralf Hoffmann <[email protected]> Wed, 20 Jan 2016 21:16:22 +0100
Newsgroups gmane.comp.file-systems.avfs.user
Message-ID <[email protected]>
Hi,

On 2016-01-19 16:40, Rich=E1rd Orosz wrote:
> I mounted a http direct url, which points to a rar file, to decompress
> it without downloading. I measured the read speed with utility "pv",
> which in fact is a filter and shows a progress indicator:
>  cat file.rar| pv |cat > file_copy.rar
>  Initial read speed is the usual 10 MB / sec, but always after reading
> 100 MB of data the read speed suddenly decreases to a few KB / sec.
>  Error log generated by option "-o debug":
> http://pastebin.com/W3Z6TMrY
> =

> I am using Arch Linux (3.14.52-1-lts)

AVFS uses a temporary cache for the downloaded content, so when you
repeat your test, the first part is already available locally and
therefore the speed is much higher. But there is nothing actually
downloaded unless you reach data which hasn't been accessed yet. So when
you hit the boundary, the speed will drop to the speed of your actual
network connection.

Best Regards,

Ralf

-- =

Ralf Hoffmann <[email protected]>
Homepage: http://www.boomerangsworld.de

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