[Xen-users] Optimising disk performance inside windows VM's

[Adam Goryachev <mailinglists@xxxxxxxxxxxxxxxxxxxxxx>]

I was wondering if anyone could provide hints/tips on how to "optimise" 
disk performance within a Windows VM.
Specifically, I'm using Windows 2008R2 with the xen GPLPV drivers 
version 8.2.0.4 from 
https://www.xenproject.org/developers/teams/windows-pv-drivers.html
My Xen config file:

builder        = 'hvm'
memory        = 20480
name        = "server"
hostname    = "server"
localtime    = 1
cpus        = "4,5,6,7,8,9,10,11"    # Which physical CPU's to allow
vcpus        = 8        # How many Virtual CPU's to present
viridian    = 1
disk        = [ 'phy:/dev/ssd/server2,xvda,w' ]
boot        = 'dc'
vif        = ['bridge=xenbr0, mac=00:16:3e:43:ab:94']
vnc        = 1
vncunused    = 0
vncdisplay    = 5
vnclisten    = '0.0.0.0'
stdvga        = 1
#videoram    = 16
usb        = 1
usbdevice    = 'tablet'
acpi        = 1
apic        = 1
on_reboot    = 'restart'
on_poweroff    = 'destroy'
on_crash    = 'restart'

I notice that this results in this fragment to qemu-system-i386:
-drive 
file=/dev/ssd/server2,if=ide,index=0,media=disk,format=raw,cache=writeback
I am curious if the ide part could be changed to help, or any of the 
other options?
Also, this document: 
https://xenbits.xen.org/docs/4.8-testing/misc/xl-disk-configuration.txt 
talk about using a "direct-io-safe" option, which can improve 
performance, where would I add that?
disk        = [ 'phy:/dev/ssd/server2,xvda,w,direct-io-safe=present' ]

Essentially, I have a simple linux software RAID1 on two SSD's, which is 
setup as a PV, I have a single LV which is then used as the disk image. 
I've seen lots of various options that can be used for the disk 
type/options/etc, but I don't really know which is the "best".
I'm using Xen 4.8.3 from Debian stable packages:
ii  grub-xen-bin 2.02~beta3-5                            amd64        
GRand Unified Bootloader, version 2 (Xen binaries)
ii  grub-xen-host 2.02~beta3-5                            amd64        
GRand Unified Bootloader, version 2 (Xen host version)
ii  libxen-4.8:amd64 4.8.3+comet2+shim4.10.0+comet3-1+deb9u5 
amd64        Public libs for Xen
ii  libxenstore3.0:amd64 4.8.3+comet2+shim4.10.0+comet3-1+deb9u5 
amd64        Xenstore communications library for Xen
ii  xen-hypervisor-4.8-amd64 4.8.3+comet2+shim4.10.0+comet3-1+deb9u5 
amd64        Xen Hypervisor on AMD64
ii  xen-linux-system-amd64 4.9+80+deb9u4                           
amd64        Xen system with Linux for 64-bit PCs (dummy package)
ii  xen-system-amd64 4.8.3+comet2+shim4.10.0+comet3-1+deb9u5 
amd64        Xen System on AMD64 (meta-package)
ii  xen-utils-4.8 4.8.3+comet2+shim4.10.0+comet3-1+deb9u5 amd64        
XEN administrative tools
ii  xen-utils-common 4.8.3+comet2+shim4.10.0+comet3-1+deb9u5 
all          Xen administrative tools - common files
ii  xenstore-utils 4.8.3+comet2+shim4.10.0+comet3-1+deb9u5 amd64        
Xenstore command line utilities for Xen
Kernel version is 4.9.82-1+deb9u3

If I should add any additional information, please let me know.

Regards,
Adam

--
Adam Goryachev Website Managers www.websitemanagers.com.au
--
The information in this e-mail is confidential and may be legally privileged.
It is intended solely for the addressee. Access to this e-mail by anyone else
is unauthorised. If you are not the intended recipient, any disclosure,
copying, distribution or any action taken or omitted to be taken in reliance
on it, is prohibited and may be unlawful. If you have received this message
in error, please notify us immediately. Please also destroy and delete the
message from your computer. Viruses - Any loss/damage incurred by receiving
this email is not the sender's responsibility.

_______________________________________________
Xen-users mailing list
Xen-users@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/xen-users