All Questions
Tagged with performance virtualization
99
questions
1
vote
1
answer
532
views
Determine QEMU KVM overhead?
My guest OS shows about 5 percent CPU usage, but my host machine shows the QEMU process taking about 25 percent.
I'm trying to understand where this difference comes from, as I am using KVM ...
- 265
0
votes
1
answer
177
views
KVM Virtualization Server - One physical disk(SSD) every virtual machine
In terms of performance,
is it better to have one "big" SSD disk for several (lets say 5) virtualized guests,
or a single smaller SSD disk for every virtual machine?
any general draw back ...
- 192
1
vote
1
answer
410
views
Raw LVM disk write is four times faster on host than inside KVM guest?
I've got a Debian 10.6 Host, with a Debian 10.6 guest. KVM/Qemu/libvirt. The host has a software RAID 10 array with 6 mechanical disks. LVM is on top of the RAID array. One LV is passed into the guest ...
- 4,503
2
votes
2
answers
2k
views
What could cause high iostat await if a disk isn't overutilized?
I have a database running on GCP. Occasionally it gets very slow for a period of minutes (like average statement execution time spikes by 10x or more). The slowness is correlated with increases in the ...
google-cloud-platform
0
votes
0
answers
135
views
How to find the bottleneck on a virtual server?
I have purchased a cheap virtual server (running with Ubuntu, with 4 virtual? CPUs and guaranteed 8GB RAM, SSD). I started Tomcat8 with my web application (with -Xmx4096m). The startup time is very, ...
- 1,423
-2
votes
2
answers
40
views
VM Performance on Different Hardware [closed]
I just bought a new server to act as a Hyper-V host for our current VMs. The hardware specs are better than our existing server (faster CPU speed, fast disk IO, etc) and I expect to see our VMs ...
1
vote
1
answer
895
views
Virtualbox performance on NUMA host (AMD Epyc)
At a small software development house, we virtualize our build servers (using VirtualBox) so that they can be easily backed up, snapshotted and the like. We've recently bought a new server using an ...
- 21
1
vote
0
answers
20
views
Hyper-V role active slows server
I've been having io performance issues with two new servers, and while testing I noticed that when I had Hyper-v turned off at boot using "bcdedit /set hypervisorlaunchtype off" that my disk tests ...
- 123
2
votes
3
answers
626
views
Performance of Dedicated vs Virtual Server
I have an application that's running in both dedicated and virtual server environments (all Windows Server 2008 R2). Given nearly identical specifications of the servers (memory, processors), the ...
- 171
1
vote
1
answer
2k
views
Questions about performance, NVMe drives and virtual machines
I currently have a 4770K with Samsung 850 Evo running Ubuntu 16.04. I create and manage VMs using vagrant with Virtual Box. I recreate VMs frequently and right now, it takes roughly 36 seconds to spin ...
- 11
23
votes
1
answer
2k
views
How to describe VMware performance requirements for our application to a VMware admin?
Often, an installation of our on-site, debian-stable based application runs in a virtual machine - typically in VMware ESXi. In the general case we do not have visibility into or influence over their ...
- 852
12
votes
1
answer
9k
views
What actually happens when I mark a disk as SSD in ESXi?
In VMWare ESXi / vSphere, you can mark a disk or LUN as "Flash", indicating that the disk is an SSD (or the LUN is SSD/flash storage backed)
When you do, you get the following warning:
Marking HDD ...
- 9,198
2
votes
1
answer
4k
views
Windows 10 esxi 6.0 performance
I'm running an ESXi 6.0.0-2494585-standard server. On this server are ~20 virtual machines running (ubuntu/suse linux & windows 7 & 10). The performance of all VMs is fine, except the windows ...
- 21
3
votes
0
answers
54
views
Do I need to create multiple filesystems on a virtual server to increase I/O performance?
I want to install Oracle on a virtual server. I don't really know the technology behind, my company just gave me a virtual server with multiple (virtual) disks.
I have the possibility to divide those ...
- 83
5
votes
1
answer
134
views
storage for virtualization: 10x15k sas w/ 2gb cache OR 10x10k sas w/ 4gb cache
sorry for the long title.
this is the point: due to a number of decisions it doesn't worth to share here and which do not completely belong to me, I'm facing the choice of 2 different storage ...
- 654
0
votes
2
answers
1k
views
OpenNebula (KVM) + OpenvSwitch, high CPU load on high bandwidth use
We are running an OpenNebula 5.0.2 environment on Ubuntu 16.04, using OpenvSwitch 2.5 for bridging the virtual interfaces and LACP trunking the two Gbit ports, which is working perfectly.
But when I ...
- 141
0
votes
2
answers
596
views
How does server virtualization increase performance? [closed]
I was reading about server virtualization as a new trend because of many benefits it brings. One of them is to increase performance with fewer hardware.
How is it possible? From my limited knowledge, ...
- 9
0
votes
2
answers
2k
views
Poor Write I/O Performance on HP ML110 G9 Server With ESXi 6.0U2
hi everyone i need a little bit of help since i cant find a solution,
i have a HP ML110 G9 Server with:
8gb Ram
2 HDD of 2tb Each one and one SSD of 250 GB
i have installed ESXi 6.0u2 HP Customized....
- 17
1
vote
2
answers
786
views
How to balance elasticsearch (java) on a very powerful machine?
On a 16 core XEON class, 128GB RAM RHEL server I want to deploy elasticsearch.
What is preferable performance-wise?
Have a huge elasticsearch process to use all resources on the native host?
Break ...
- 577
2
votes
1
answer
2k
views
Performance impact enabling intel vt-x
I have a rather unusual question: What is the performance impact when you enable vt-x and you don't need it?
I ask this because all of the new servers I receive have this enabled by default in the ...
- 968
1
vote
0
answers
461
views
iperf actual send rate always lower than the expected target bandwidth until some equilibrium reached. Why?
I did an UDP iperf 2.0.5-Ubuntu test between two VMs on the same hypervisor. As can be seen in the iperf output below I started my first test with "-b 686M" flag. However, iperf reported that it was ...
- 113
1
vote
3
answers
2k
views
How can I determine the performance penalty of VT-d vs. baremetal?
I am looking to configure my server in a slight odd way to create a private cloud setup.
I have to take the HBA that my storage disks are tied to and pass it into a VM (probably xen) to allow the ...
- 1,975
4
votes
1
answer
2k
views
KVM bad IO sync performance in Linux guest
I'm setting up virtualized Ubuntu 15.10 guest inside Ubuntu 15.04 server using libvirt and KVM.
Storage in host system:
# mount | grep ext4
/dev/sda1 on / type ext4 (rw,relatime,errors=remount-ro,...
- 141
4
votes
3
answers
346
views
Which VM needs more resources?
I have a physical server which runs 8 virtual machines with virt-manager and kvm.
Since one VM is not needed any more, I want to give the remaining virtual machines more resources.
I'm looking for ...
- 3,603
2
votes
1
answer
2k
views
How much of a performance does using QEMU virtualization incur on Windows?
How much of a performance does using QEMU virtualization incur on a Windows host, when both the host and vm are running the same CPU?
Older articles indicate that using kqemu avoided the slow down in ...
- 1,632
4
votes
2
answers
6k
views
How to interpret values of Perfmon counter Hyper-V Hypervisor Virtual processor\CPU Wait time per dispatch
So there is a lot of guidance on the web that advises tracking the values of the Perfmon counter Hyper-V Hypervisor Virtual processor\CPU Wait time per dispatch as the nearest Hyper-V equivalent of ...
- 654
19
votes
3
answers
5k
views
Is running permanently in a VMWare snapshot bad for performance?
I understand that the VMWare KB frowns upon long running snapshots mainly due to two things (In my opinion)
Taking tons of snapshots can fill up the data store. Snapshots are simply delta files. ...
-1
votes
1
answer
413
views
clonehd takes 2 hours for a 100GB disk. Expected? [closed]
I have a VirtualBox image using VDI and flexible size. Right now the physical DVI file 94GB. The host is an Ubuntu server and the guest is a CentOS 6.4 with ext4 partition. The host is using a sata ...
9
votes
5
answers
36k
views
How to speed up QEMU on Windows host?
We want to run our Ubuntu 64bit web server virtualized/emulated on a Windows 64bit host. Intended use is to distribute the VM to customers who might not have "elevated" or "admin" rights on the ...
- 101
5
votes
4
answers
776
views
Setting the noatime flag for filesystems inside an lxc container
My host filesystem is ext4 mounted with the noatime flag. But inside an lxc-container, the flag is absent.
Here's the output of mount on the host:
/dev/sdb1 on /home type ext4 (rw,noatime)
And here'...
- 225
62
votes
10
answers
15k
views
How to [politely?] tell software vendor they don't know what they're talking about
Not a technical question, but a valid one nonetheless. Scenario:
HP ProLiant DL380 Gen 8 with 2 x 8-core Xeon E5-2667 CPUs and 256GB RAM running ESXi 5.5. Eight VMs for a given vendor's system. ...
- 5,232
1
vote
0
answers
41
views
How to compare and state performance on virtual server instance?
I want to report performance statistics about an algorithm that runs on a virtual server instance with Ubuntu on it. I measured runtime and maximum memory usage but I want to give a statement about ...
- 205
4
votes
6
answers
2k
views
When is it time to add more cores to your virtual server? [closed]
I have a Linux (RHEL 5.8) server with Java 7 and Tomcat 7.
The performance is poor, and I am pretty sure it's the DB queries that are slow.
We have 2 cores right now, and load average never exceeds ...
- 616
5
votes
2
answers
1k
views
Does LXC container performance depends of host load?
I am wondering if LXC could offer a full isolated benchmarking environment.
Let's say we have 2 identical machines, with the same fresh Linux and without network connection.
First machine has a load ...
0
votes
1
answer
179
views
How to benchmark a whole storage infrastructure
I'm a 100% sure that I'm not the first one to consider benchmarking a whole infrastructure, but yet I haven't found any relevant information on how to face this challenge.
As I guess we all know what ...
user294330
-1
votes
1
answer
191
views
Server Hardware/Settings for high traffic [duplicate]
I'm currently using a virtual server.
2 vCores 8GB RAM Bandwith 100MBit/s Ubuntu 10.04
But still this seems to be not enough to handle the traffic on my site. Normally a page needs less than 0....
0
votes
2
answers
762
views
Very fast virtual machine rollback [closed]
Summary: Is there a VM that's optimized for fast in-memory rollback to a previous state?
I've tried in vain on StackOverflow and SuperUser — maybe this is the right place to ask this question. :)
I'...
6
votes
1
answer
1k
views
Ext4 cache options on a virtual machine
I'm trying to speed up a standup of virtual machines used for development / automated test environments and wanted to verify some assumptions about disk writes caching.
I'm using ext4 for the root ...
- 1,296
0
votes
3
answers
5k
views
Increasing vCPUs for Server 2003?
I have a VM running Server 2003 and SQL Server 2008 on VMware ESXi. Can I safely assume this configuration can cope with a change to the number of vCPUs? Are there better solutions to address the ...
- 123
1
vote
1
answer
135
views
Hyper-V and CPU Usage
I'm renting VPS that I believe is using Hyper-V. Lately the processor performance of my VPS has been terrible, yet the CPU usage in the task manager doesn't show it struggling. Is the CPU usage in the ...
- 123
2
votes
1
answer
95
views
Are graphic capabilities included in CPU used in common servers (web + thinclient)?
I'm trying to decide between these two Intel processors
The first of them has no graphic support in core.
I know that this type of graphic "cards" can be used to execute code from common (non-...
- 223
2
votes
1
answer
1k
views
Under what circumstances could adding a CPU to an "underutilized" VMware vSphere 4.1 VM increase performance?
Scene: 16-core VMware ESX 4.1 host. Presume that the host is not over loaded in any single resource at all. Storage latencies are very low, total memory utilization is below the physical ram amount, ...
- 626
8
votes
1
answer
869
views
virtual disk image - file or partition
I'm looking at the differences between using a file versus a partition to store a virtual disk image in VM use. The common knowledge is that partition-based images are faster than file-based images ...
- 15.1k
4
votes
2
answers
4k
views
Does Proxmox VE Support LVM as block storage for KVM guests?
Does Proxmox VE Support LVM as block storage for KVM guests to avoid the overhead of going through the filesystem layer on the host system ?
- 41
16
votes
2
answers
2k
views
Can a virtualized machine have the CPU and RAM resources of multiple underlying physical machines?
We are studying implementing some virtualized servers here, but we don't know what will be better suitable for us. Some folks are saying better have two huge servers, and others are saying have like a ...
- 295
0
votes
1
answer
1k
views
High CPU Steal percentage on Amazon EC2 Instance
I am experiencing high CPU steal percentage in a Amazon EC2 large instance. I know it means that my virtual CPU is waiting on the real CPU of the machine for time. My question is that what can I do to ...
- 1,065
-1
votes
4
answers
648
views
Does shutdown idle VMs improve the performance?
Often our team members are coming to me with a compliant that their VMs are slow.
Our team members suggested to shutdown some of the VMs temporarily and try to access the VM.
But most cases that ...
- 1,311
1
vote
1
answer
1k
views
How do I measure and compare disk performance of my Hyper-V Windows VM?
I'm not sure whether this sounds stupid or lazy, but I'm really not sure.
I have a problem with the performance of a VM setup (2008R2-64bit Hyper-V running a 2003R2-32bit Windows server) and I'd like ...
- 599
4
votes
3
answers
3k
views
How to find virtualization performance bottlenecks?
We have recently started moving our C++ build server(s) from real machines into VMs. (MS Hyper-V)
We have some performance issues that I've currently no idea how to address. We have:
Test-Box - this ...
- 599
1
vote
1
answer
2k
views
Are intermittently slow disk read speeds ever caused by the OS itself?
I'm noticing intermittently slow disk read/write speeds on my CenTOS 5.x VM.
Sometimes hdparm will report:
/dev/sda3:
Timing buffered disk reads: 6 MB in 3.03 seconds = 2.04 MB/sec
Other ...
- 11.9k