Problems with Windows XP KVMs

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MJennings

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Hi again.. on my bi quad core server with 16GB ram, I'm having problems running 7 XP KVMs. All VM's have 1GB ram. I am monitoring my proxmox server load every 5 minutes for the past 3 days. The highest load average says this:
Code: 
load average: 5.90, 4.15, 2.76
My users are connecting via RDC of course. But I have people who are complaining about their VMs locking up and just being generally laggy, and even after they reboot their VMs they are still experiencing the problem. Some say they cannot login to their VMs for about 20 minute periods when it gets really bad. Also a lot of them are saying when their VM gets laggy, their cpu will say a high load average from 60-80%, even when all of their applications are closed and only the standard XP services/background processes are running. Does anyone know what's wrong here? or where I should start looking?
 
MJennings said:
Hi again.. on my bi quad core server with 16GB ram, I'm having problems running 7 XP KVMs. All VM's have 1GB ram. I am monitoring my proxmox server load every 5 minutes for the past 3 days. The highest load average says this:
Code: 
load average: 5.90, 4.15, 2.76
My users are connecting via RDC of course. But I have people who are complaining about their VMs locking up and just being generally laggy, and even after they reboot their VMs they are still experiencing the problem. Some say they cannot login to their VMs for about 20 minute periods when it gets really bad. Also a lot of them are saying when their VM gets laggy, their cpu will say a high load average from 60-80%, even when all of their applications are closed and only the standard XP services/background processes are running. Does anyone know what's wrong here? or where I should start looking?
Click to expand...
Hi,
perhaps IO-related?
Which IODelay do you have in cases of high load?
What is the output of pveperf ?

How much cores/CPUs do you have assigned to the VMs?

Udo
 
Do you mean the wa% ?

Code: 
top - 21:20:01 up 12 days, 19:09,  1 user,  load average: 5.90, 4.15, 2.76
Tasks: 242 total,   3 running, 239 sleeping,   0 stopped,   0 zombie
Cpu(s): 17.7%us,  4.9%sy,  0.0%ni, 76.9%id,  0.3%wa,  0.0%hi,  0.1%si,  0.0%st
Mem:  16433620k total, 16332496k used,   101124k free,   129796k buffers
Swap:  8191992k total,     2692k used,  8189300k free,  6044500k cached

Code: 
CPU BOGOMIPS:      32000.41
REGEX/SECOND:      397119
HD SIZE:           14.53 GB (/dev/sda1)
BUFFERED READS:    119.17 MB/sec
AVERAGE SEEK TIME: 7.90 ms
FSYNCS/SECOND:     535.78
DNS EXT:           17.58 ms
DNS INT:           99.04 ms (mysite.com)

I have assigned one cpu and one core. Someone on a windows forum says you have to have paravirtualized drivers for all hardware inside the VM and that's why the VM is running so slowly. Might this be the issue? I am using virtio driver for network but not for storage.
 
MJennings said:
Do you mean the wa% ?

Code: 
top - 21:20:01 up 12 days, 19:09,  1 user,  load average: 5.90, 4.15, 2.76
Tasks: 242 total,   3 running, 239 sleeping,   0 stopped,   0 zombie
Cpu(s): 17.7%us,  4.9%sy,  0.0%ni, 76.9%id,  0.3%wa,  0.0%hi,  0.1%si,  0.0%st
Mem:  16433620k total, 16332496k used,   101124k free,   129796k buffers
Swap:  8191992k total,     2692k used,  8189300k free,  6044500k cached
Code: 
CPU BOGOMIPS:      32000.41
REGEX/SECOND:      397119
HD SIZE:           14.53 GB (/dev/sda1)
BUFFERED READS:    119.17 MB/sec
AVERAGE SEEK TIME: 7.90 ms
FSYNCS/SECOND:     535.78
DNS EXT:           17.58 ms
DNS INT:           99.04 ms (mysite.com)
I have assigned one cpu and one core. Someone on a windows forum says you have to have paravirtualized drivers for all hardware inside the VM and that's why the VM is running so slowly. Might this be the issue? I am using virtio driver for network but not for storage.
Click to expand...
Hi,
yes i mean wait - the pve-gui shows this value in the home-section as IODelay.

It's curios, that your wait are only 0.3% and the cpu are only 17% but the load at 5.
I'm right, that you have 8 cores? So you don't have trouble with an load below 8.
What format for the virtual disk you use? raw or qcow2?
The perfdata looks, that you use a single disk and not a raid, right?

Better IO you get with diskformat raw and using the virtio-driver (you find postings about how to convert in the forum). With the virtio network driver i had sometime problems under high load, so i use at this time the e1000-driver.
Of course will the speed (fsyncs/s + rw) much better with a good raid controller (and disks).

Udo
 
Yes.. IO is showing very low at any point in time. I have the first 10 lines of "top" recorded to file every 5 minutes so I can go back and see loads when a user complains. Yes I have 8 cores. I am using raw format, I have two large disks added in my LVM and mounted to /var/lib/vz. I am going to try virtio driver for storage if I can figure out how to get it working (windows installer says no disk detected). But even if I try virtio driver for storage and network, will it make that much of a difference? Don't I need a paravirtualized driver for CPU too?
 
MJennings said:
Yes.. IO is showing very low at any point in time. I have the first 10 lines of "top" recorded to file every 5 minutes so I can go back and see loads when a user complains. Yes I have 8 cores. I am using raw format, I have two large disks added in my LVM and mounted to /var/lib/vz. I am going to try virtio driver for storage if I can figure out how to get it working (windows installer says no disk detected). But even if I try virtio driver for storage and network, will it make that much of a difference? Don't I need a paravirtualized driver for CPU too?
Click to expand...

Hi,
for use virtio (in short):
Install normal on ide
get the newest virtio-driver (redhat) on the client
add a virtio-disk (as dummy). Stop/Start
Windows ask for the driver - install.
Stop Windows. Delete both disks in the gui and add again the unused systemdisk as virtio 0:0.
Delete the dummy disk from disk
Windows should boot, then the driver for virtio 0:0 is installed.

For the CPU you don't need a driver - so to speak it is done in hardware with the virtualisation of the cpu (svm/vmx).

Udo
 
OK, got virtio storage and network both installed. I will see if this makes a difference. But the problem doesn't appear to be IO so I don't think it will make a difference. Is raw format ok to use? And is my disk setup ok with two disks in LVM? I have all my KVMs set to 1000 cpuunits, if I increase this will it fix the problem? or is this problem unrelated to that
 
MJennings said:
OK, got virtio storage and network both installed. I will see if this makes a difference. But the problem doesn't appear to be IO so I don't think it will make a difference. Is raw format ok to use? And is my disk setup ok with two disks in LVM? I have all my KVMs set to 1000 cpuunits, if I increase this will it fix the problem? or is this problem unrelated to that
Click to expand...
Hi,
raw-format is fine!
Your disk setup is ok, but not safe (if one disk die, you lose perhaps not all but to much) and not fast. If your VMs are in production use, buy a good raidcontroller with at least 3 disks (in raid5).
Better are raid 10 with 4 disks. Only for comparison the output of pveperf wit an 4-SAS-Disk Raid10 (areca controller):
Code: 
# pveperf /var/lib/vz
CPU BOGOMIPS:      27293.44
REGEX/SECOND:      886668
HD SIZE:           543.34 GB (/dev/mapper/pve-data)
BUFFERED READS:    478.39 MB/sec
AVERAGE SEEK TIME: 5.61 ms
FSYNCS/SECOND:     5327.25
DNS EXT:           85.79 ms
DNS INT:           0.61 ms
OK, not cheap, but worthwhile.

The cpuunits are relative - it's to priorisation of several VMs. So normaly it's fine to take the same value for each client.

Udo
 
I am renting my server from a datacenter, so don't have much control over the hardware. But my setup with two LVMs is faster than one hdd by itself, right? And should I have put the two hdds in a raid with mdadm before doing a LVM on it? And cpu units are only for priority? it does not mean the cpu will start to slow down for the VM after it passes 1000 units?
 
MJennings said:
I am renting my server from a datacenter, so don't have much control over the hardware. But my setup with two LVMs is faster than one hdd by itself, right?
Click to expand...
Right!
And should I have put the two hdds in a raid with mdadm before doing a LVM on it?
Click to expand...
Softwareraids are not supported by proxmox, but there are some (a lot) posts about that. But i'm no expert for softwareraids - i used it for some servers (with good experience) but not with proxmox.
And cpu units are only for priority? it does not mean the cpu will start to slow down for the VM after it passes 1000 units?
Click to expand...
Yes! I have some VMs with heavy load (windows) on two pve-servers. All VMs has the same value for cpu unit and nothing slow down...

Udo
 
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