From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
To: Steven Haigh <netwiz@crc.id.au>
Cc: "xen-devel@lists.xen.org" <xen-devel@lists.xen.org>,
"Roger Pau Monné" <roger.pau@citrix.com>
Subject: Re: 4.2.1: Poor write performance for DomU.
Date: Tue, 12 Mar 2013 09:04:30 -0400 [thread overview]
Message-ID: <20130312130430.GA17901@phenom.dumpdata.com> (raw)
In-Reply-To: <513DDE07.2090607@crc.id.au>
> >So still filesystem. Fio can do it on a block level.
> >
> >What does 'xenstore-ls' show you and 'losetup -a'? I am really
> >curious as to where that file you are providing to the guest as
> >disk is being handled via 'loop' or via 'QEMU'.
> >
>
> I've picked out what I believe is the most relevant from xenstore-ls
> that belongs to the DomU in question:
Great.
.. snip..
> params = "/dev/vg_raid6/fileshare"
> mode = "w"
> online = "1"
> frontend-id = "1"
> type = "phy"
> physical-device = "fd:5"
> hotplug-status = "connected"
> feature-flush-cache = "1"
> feature-discard = "0"
> feature-barrier = "1"
> feature-persistent = "1"
> sectors = "5368709120"
> info = "0"
> sector-size = "512"
OK, so the flow of data from the guest is:
bonnie++ -> FS -> xen-blkfront -> xen-blkback -> LVM -> RAID6 -> multiple disks.
Any way you can restructure this to be:
fio -> xen-blkfront -> xen-blkback -> one disk from the raid.
to see if the issue is between "LVM -> RAID6" or the "bonnie++ -> FS" part?
Is the cpu load quite high when you do these writes?
What are the RAID6 disks you have? How many?
next prev parent reply other threads:[~2013-03-12 13:04 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-02-20 2:10 4.2.1: Poor write performance for DomU Steven Haigh
2013-02-20 8:26 ` Roger Pau Monné
2013-02-20 8:49 ` Steven Haigh
2013-02-20 9:49 ` Steven Haigh
2013-02-20 10:12 ` Jan Beulich
2013-02-20 11:06 ` Andrew Cooper
2013-02-20 11:08 ` Steven Haigh
2013-02-20 12:48 ` Andrew Cooper
2013-02-20 13:18 ` Pasi Kärkkäinen
2013-03-08 20:42 ` Konrad Rzeszutek Wilk
2013-03-08 8:54 ` Steven Haigh
2013-03-08 9:43 ` Roger Pau Monné
2013-03-08 9:46 ` Steven Haigh
2013-03-08 9:54 ` Roger Pau Monné
2013-03-08 20:49 ` Konrad Rzeszutek Wilk
2013-03-08 22:30 ` Steven Haigh
2013-03-11 13:30 ` Konrad Rzeszutek Wilk
2013-03-11 13:37 ` Steven Haigh
2013-03-12 13:04 ` Konrad Rzeszutek Wilk [this message]
2013-03-12 14:08 ` Steven Haigh
[not found] ` <514EA337.7030303@crc.id.au>
[not found] ` <514EA6B0.8010504@crc.id.au>
[not found] ` <514EA741.7050403@crc.id.au>
2013-03-24 9:10 ` Steven Haigh
2013-03-24 9:54 ` Steven Haigh
2013-03-25 2:21 ` Steven Haigh
2013-08-20 16:48 ` Konrad Rzeszutek Wilk
2013-08-20 18:25 ` Steven Haigh
2013-09-05 8:28 ` Steven Haigh
2013-09-06 13:33 ` Konrad Rzeszutek Wilk
2013-09-06 23:06 ` Steven Haigh
2013-09-06 23:37 ` Konrad Rzeszutek Wilk
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