From: Michal Soltys <soltys@ziu.info>
To: Zoltan Szecsei <zoltans@geograph.co.za>
Cc: linux-raid@vger.kernel.org
Subject: Re: Array read 3 time slower to read after data fully loaded
Date: Thu, 18 Nov 2010 21:43:37 +0100 [thread overview]
Message-ID: <4CE58FF9.3050202@ziu.info> (raw)
In-Reply-To: <4CE4B9E6.1040802@geograph.co.za>
On 10-11-18 06:30, Zoltan Szecsei wrote:
> Hi,
> Can anyone please explain this to me?
>
> For the last >30 hours I have been loading some 2.5TB of 200-400MB tiff
> images, from another PC on our internal network, onto this new array.
> Yesterday, during this load process, I copied 10 of these files (about
> 2.5GB) from the array onto the /home directory of the same system.
>
> It took 33 seconds, equating to some 75MB/s.
>
> This morning I came in to find that the load process had finished, so I
> deleted the 10 test files from /home, and redid the identical copy test
> (using bash-history, so: identical).
>
> It took 123 seconds, equating to some 20MB/s.
>
> Que? (as in Manuel from Faulty Towers :-) )
>
Is the situation with reading into /dev/null instead of /home the same ?
As this is reading issue, one thing that came to my mind:
- make sure the kernel is _not_ compiled with CONFIG_MULTICORE_RAID456.
It's afaik still experimental and can cause severe slowdowns
next prev parent reply other threads:[~2010-11-18 20:43 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-11-18 5:30 Array read 3 time slower to read after data fully loaded Zoltan Szecsei
2010-11-18 20:43 ` Michal Soltys [this message]
2010-11-18 20:53 ` David Lethe
2010-11-22 4:18 ` Neil Brown
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=4CE58FF9.3050202@ziu.info \
--to=soltys@ziu.info \
--cc=linux-raid@vger.kernel.org \
--cc=zoltans@geograph.co.za \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.