From: L A Walsh <lvm@tlinx.org>
To: LVM general discussion and development <linux-lvm@redhat.com>
Subject: Re: [linux-lvm] pvmove speed
Date: Fri, 17 Feb 2017 15:00:25 -0800 [thread overview]
Message-ID: <58A78089.7020202@tlinx.org> (raw)
In-Reply-To: <2118934913.869.1487344329807.JavaMail.zimbra@karlsbakk.net>
Roy Sigurd Karlsbakk wrote:
> I get 200MB on a cold day and 500 on a nice one from this SAN. These 40-50MB/s seem really being limited by pvmove alone. Nothing else shows this limit. That's why I'm asking.
>
---
200-500... impressive for a SAN... but considering the bandwidth
you have to the box (4x1+10), I'd hope for at least 200 (what I get
w/just a 10)... so must be some parallel TCP channels there... he..
What showed those speeds? I'm _guessing_, but its likely that pvmove
is single threaded. So could be related to the I/O transfer size as
@pattonme was touching on, since multi-threaded I/O can slow things
down for local I/O when local I/O is in the .5-1GBps and higher range.
Curious -- do you know your network's cards' MTU size?
I know that even w/1Gb cards I got 2-4X speed improvement over
standard 1500 packets (run 9000/9014 byte MTU's over local net).
I'd have to look at the source for more info...
-l
next prev parent reply other threads:[~2017-02-17 23:00 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-02-11 8:59 [linux-lvm] pvmove speed Roy Sigurd Karlsbakk
2017-02-16 18:22 ` Roy Sigurd Karlsbakk
2017-02-17 0:44 ` L A Walsh
2017-02-17 1:24 ` pattonme
2017-02-17 15:12 ` Roy Sigurd Karlsbakk
2017-02-17 17:01 ` John Stoffel
2017-02-17 17:33 ` Roy Sigurd Karlsbakk
2017-02-17 23:00 ` L A Walsh [this message]
2017-02-18 8:12 ` Roy Sigurd Karlsbakk
2017-02-18 16:55 ` Mark Mielke
2017-02-20 9:59 ` Zdenek Kabelac
2017-03-31 16:27 ` Roy Sigurd Karlsbakk
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=58A78089.7020202@tlinx.org \
--to=lvm@tlinx.org \
--cc=linux-lvm@redhat.com \
/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.