Is the free VMWARE server suitable for production use?
- http://www.vmware.com/community/message.jspa?messageID=590461 - Lots of people claiming to use it for production. More flexible than ESX.
According to a VMWare staffer: "we have customers using VMware Server on 8 way boxes with 32GB of RAM in a production environment."
- http://briandowney.net/blog/2007/03/30/vmware-server-in-production/
- our environment regularly goes as much as six months without needing to take it down-and generally for some unrelated reason or to simply upgrade VMware itself. You cannot get the same performance numbers or quantity of VMs on a host as ESX, nor can you do the magic of balancing resources, but in most small environments that isn't necessarily needed or even a problem.
- Other tips to allow 4-6 moderately loaded VMs per physical core (usually suggest 2-4 with server, and 4-8 with ESX)
- Avoid swamping out the NIC - trunk 2,3,4 ports in a load balance
- Host OS: Recommends CentOS in Minimal installation, update it once, install vmware, then don't touch it.
- Tune VMs carefully
- busy Apache VMs can get away with as little as 192MB of RAM,
- DNS servers running djbdns usually do fine with 96MB of RAM.
- Avoid multiple CPUs in a VM
- ESX roughly doubles the number of VMs per host
- Bottlenecks:
- Disk I/O is the first - high quality SAS/SCSI with lots of cache helps
- Cheap ethernet based san using RHCS (CentOS) and GNBD.
- Load Testing a Virtual Web Application
- our public web server, which gracefully survived the slashdotting with barely a hiccup, is running on the very same free version, along with a number of other hosted VMs.
- These results indicate that a virtualized server running a typical web application may experience a 43% loss of total capacity when compared to a native server running on equivalent hardware.
- Note they did not attempt to tune for the virtual environment.
- More discussion by VMWare about this
- http://searchservervirtualization.techtarget.com/expert/KnowledgebaseAnswer/0,289625,sid94_gci1213352,00.html
- Production SQL server - good for virtualization unless very high performance is required
According to Xensource:
- Neither VMware Server nor Microsoft Virtual Server is considered useful for virtualization of production or performance sensitive workloads because the hosted model imposes severe performance overheads due to the need to emulate the virtualized hardware layer. As a result, neither of these products is considered in this study.
- VMware's End User License Agreement (EULA) prohibits licensees from publishing performance benchmarks without VMware's permission, arguing that poorly constructed benchmarks could damage its credibility with customers.
Drawbacks on baremetal solutions
- Only hardware which has its drivers included will work.
- For example: Problems with USB drives only partially working on Virtual Iron
- For example: VMWare may have problems with SATA disks.
Hosted solution (VMWare server) allows anything the OS can do, like connecting a remote iSCSI disk or driving a local tape backup unit, is immediately available for Server virtual machines use.
Sources:
- http://www.virtualization.info/2006/12/choosing-between-vmware-server-and-esx.html (Rambling article, but helpful)
Possible limit on virtual machines
But one limit you might hit is the limit of 64 vcpus. This means that you can only run 32 vsmp VMs or 64 uni cpu VMs on one host. On ESX3 the limit is 128 vcpus and in ESX2 the limit is 80.
Host disk thrashing
> It all works very well indeed - except just sometimes
> (when I use remote console or VirtualCentre) the host
> will hang - no CPU time being used, but loads of disk
> thrashing. When left alone for a few minutes it sorts
> itself out and all the guests carry on as if nothing
> happened.
Add the following lines to your .vmx files and restart VMs:
sched.mem.pshare.enable = "FALSE"
mainMem.useNamedFile = "FALSE"
MemTrimRate = "0"
- NOTE: The user said this didn't help.
ESX Server vs. VMWare free server
- At this point, Gupta is leaning toward ESX, despite the clear success he's achieved using the free version. "From an ease-of-use perspective [~admin:VMware Server] wins out every time, hands down," he said. VMware Server, the free successor to GSX, runs on a Windows platform and includes a GUI. Compare that to the bare-metal ESX, with which "you need to know command line, you need to know scripting." - http://searchwinit.techtarget.com/originalContent/0,289142,sid1_gci1218434,00.html