Re: [linux-lvm] pvmove speed

[Roy Sigurd Karlsbakk <roy@karlsbakk.net>]

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.

Vennlig hilsen / Best regards

roy
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Roy Sigurd Karlsbakk
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----- Original Message -----
> From: "L A Walsh" <lvm@tlinx.org>
> To: "linux-lvm" <linux-lvm@redhat.com>
> Sent: Friday, 17 February, 2017 01:44:36
> Subject: Re: [linux-lvm] pvmove speed

> Roy Sigurd Karlsbakk wrote:
>>> I'm doing pvmove of some rather large volumes from a Dell Equallogic system to
>>> Dell Compellent. Both are connected on iSCSI ....
> ----
>    I've never had very great speeds over a network.  I've gotten the
> impression
> that iSCSI is slower than some other network protocols.
> 
>    Locally (RAID=>RAID) I got about 400-500MB/s, but the best I've
> gotten, recently, over a 10Gb network card has been about 200MB/s.
> Oddly, when I first got the cards, I was getting up to 400-600MB/s, but
> after MS started pushing
> Win10 and "updates" to Win7 (my communication has been between
> Win7SP1<->linux server), my speed dropped to barely over 100MB/s which
> is about what I got with
> a 1Gb card.  I wasn't able to get any better speeds using *windows*
> single-threaded SMB proto even using 2x10Gb (have a dedicated link tween
> workstation and server) -- but I did notice the cpu maxing out on either the
> windows or the Samba side depending on packet size and who was doing the
> sending.
> 
>    50MB sounds awfully slow, but not out of the ballpark -- I had
> benched a few
> NAS solutions @ home, but could rarely get about 10MB/s (usually
> slower), so gave up on those and went w/a linux server -- but still alot
> slower than I'd
> like (100-200MB/s sustained, but those figures may change w/the next MS
> "update").  But gave up on commercial, out-of-the-box solutions, and the
> 4x1Gb
> connect you have may be costing you more cpu than its worth... Problem I
> noted
> on 2x10G was too many duplicate packets -- so running 1x10Gb now but
> still maxing out around 200MB/s over an unencrypted SMB/CIFS session.
> 
>    I'm not sure it could be an LVM problem given its local speed for
> pvmoves --
> do you have some measurement of faster file I/O throughput using iSCSI
> over your
> connections?
> 
> 
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