Piotr Jasiukajtis wrote:
On Mon, Feb 16, 2009 at 4:55 PM, Mark Johnson <[email protected]> wrote:
Piotr Jasiukajtis wrote:
Hi,
How can I improve performance of Windows XP / Windows Server 2003
using .vmdk files?
The guests are extremely slow on .vmdk files instead of raw zvols.
They shouldn't be...
Are you using PV drivers? What's the disk entry on the
guest?
No PV drivers.
You really should be using PV drivers. IO performance
is very bad without them :-)
Without PV drivers, all the disk accesses are done
in the qemu code.. i.e. your not using a blockend driver
at all (although they are loaded in case you install
PV drivers).
xm list -l <guest>
e.g. here's one of mine..
(device
(tap
(uuid b6493411-5a81-798c-8683-d3e60e817e5a)
(bootable 0)
(dev hda:disk)
(uname tap:vdisk:/tank/guests/windows7/disk0)
(mode w)
(backend 0)
)
(device
(tap
(uname tap:vdisk:/export/xvm/isos/test.vmdk)
(uuid 64df266d-6b58-0d26-ab4c-29a2b7d21c2f)
(mode w)
(dev hda:disk)
(backend 0)
(bootable 1)
)
)
looks good.
How disk you create the vmdk file? With vdiskadm?
No, it's created from physical machine via vmware converter.
ok. On a side note, one of these days we will be
putting back convert functionality so you can be
moving between a vmdk, vdi, vhd, and a zvol, disk,
etc.
Is the disk on a local filesystem? If so UFS or ZFS?
Local disk ZFS root. SXCE107.
I assume you are limiting the zfs ARC cache? You have to
do this for dom0.
If ZFS, did you set the record size to 8k (zvols default
to 8K.
i.e.
# zfs get recordsize tank/guests
: alpha[1]#; zfs set recordsize=8k tank/guests
: alpha[1]#; zfs get recordsize tank/guests
NAME PROPERTY VALUE SOURCE
tank/guests recordsize 8K local
: alpha[1]#;
My vmdk file:
# ls -alh /export/xvm/isos/test.vmdk
-rw------- 1 xvm root 1,9G lut 17 11:44 /export/xvm/isos/test.vmdk
# zfs get recordsize rpool/export/xvm/isos
NAME PROPERTY VALUE SOURCE
rpool/export/xvm/isos recordsize 128K default
Can you try setting this to 8k, then moving the file
out, then back into the zfs filesystem?
MRJ
# zfs get recordsize rpool/export/xvm
NAME PROPERTY VALUE SOURCE
rpool/export/xvm recordsize 128K default
My ZVOL:
# zfs get recordsize rpool/export/xvm/winsrv2_c
NAME PROPERTY VALUE SOURCE
rpool/export/xvm/winsrv2_c recordsize - -
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