RE: [Xen-users] poor performance of hard disk in Windows DomU with Xen 4.0

[Zary Matej <matej.zary@xxxxxxxxx>]

>________________________________________
>From: xen-users-bounces@xxxxxxxxxxxxxxxxxxx 
>[xen-users-bounces@xxxxxxxxxxxxxxxxxxx] On Behalf Of Flako [subforos@xxxxxxxxx]
>Sent: 29 June 2011 20:30
>To: xen-users@xxxxxxxxxxxxxxxxxxx
>Subject: [Xen-users] poor performance of hard disk in Windows DomU with Xen    
> 4.0
>
>Hello
>I have a PC/Server with 2 Intel E6220 with 16GB ram, running Debian GNU / 
>Linux 6.0 with kernel 2.6.32-5-xen-amd64.
>Adaptec controller has an ASR-2405 and am using the last module aacraid.ko 
>(version 1.1-7 [28000]-ms)
>
>I have a significant drop in disk access performance when virtualizing Windows 
>2003 32Bit (Xen 4.0) and not if a topic module Xen aacraid.ko or incompatible 
>with the module definition or bad domU
>
>I agracere any suggestions of where else to look.
>Below I detail my confuracion
>
>
>/-- In the controller, I have 4 drives (2 RAID 1)
>subsystem: Adaptec ASR-2405
>scsi0 : aacraid
>scsi 0:0:0:0: Direct-Access     Adaptec  R1sata           V1.0 PQ: 0 ANSI: 2
>scsi 0:0:1:0: Direct-Access     Adaptec  R1sas            V1.0 PQ: 0 ANSI: 2
>scsi 0:1:0:0: Direct-Access     WDC      WD5000AAKS-0     01.0 PQ: 1 ANSI: 5
>scsi 0:1:1:0: Direct-Access     WDC      WD5000AAKS-0     01.0 PQ: 1 ANSI: 5
>scsi 0:1:2:0: Direct-Access     SEAGATE  ST3300657SS      0006 PQ: 1 ANSI: 5
>scsi 0:1:3:0: Direct-Access     SEAGATE  ST3300657SS      0006 PQ: 1 ANSI: 5
>\-- In the controller, I have 4 drives (2 RAID 1)
>
>/--- The loaded modules are:
>lsmod | grep ata
>ata_generic             3239  0
>ata_piix               21124  0
>libata                133744  2 ata_generic,ata_piix
>scsi_mod              126501  5 sg,sr_mod,sd_mod,libata,aacraid
>\--- The loaded modules are:
>
>
>The performance of rad 1 (with two SAS drives) with "hdparm-tT / dev / sdb" is:
>/dev/sdb:
>Timing cached reads:   15192 MB in  1.99 seconds = 7636.45 MB/sec
>Timing buffered disk reads: 434 MB in  3.01 seconds = 144.02 MB/sec
>
>In this link you can see the performnce the SAS disk partition, with the 
>parameter phy.
>http://img96.imageshack.us/img96/7485/discosaswindowsdomu1.jpg
>
>In this link you can see that achieves performnce windows 2003 32bit host 
>(native) of the same disk partition SAS
>http://img838.imageshack.us/img838/7610/discosaswindowshost.jpg
>
>The xm dmesg is in the link
>http://www.fileupyours.com/view/309484/xm_dmesg.txt
>
>/---------The domU.cfg is:
>kernel = '/usr/lib/xen-default/boot/hvmloader'
>device_model = '/usr/lib64/xen/bin/qemu-dm'
>builder = 'hvm'
>maxmen = '9216'
>memory = '9216'
>shadow_memory = 87
>acpi = 1
>apic = 1
>pae = 1
>vcpus =16
>videoram = 16
>
>disk = [
>        'phy:/dev/gv_db/vl2,ioemu:hda,w'
>        ,'phy:/dev/gv_db/vl1,ioemu:hdb,w'
>        ,'file:/mnt/domains/atreuco/disco3.img,ioemu:hdc,w'
>       ,'phy:/dev/sdb2,ioemu:hdd,w'
>]
>boot='c'
>e1000=1
>vif = ['type=ioemu, bridge=eth0' ]
>usb =1
>usbdevice = 'host:0925:01003'
>\---------The domU.cfg is:
>
>Thank you for reaching this far down ...
>Sorry for English, this is google:)
>

You should use PV drivers to improve the IO performance (otherwise the fully 
emulated IO hampers the performance).

For example look here: http://wherethebitsroam.com/content/gplpv
_______________________________________________
Xen-users mailing list
Xen-users@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-users