Облачные и VPS виртуалки: Как определить, какая система виртуализации на вашем хостинге.

Frequently, customers want to install software in a virtual machine. This can be OK, but frequently they hit a CPU,memory, or IO limit caused by running in a constrained virtual environment.When this happens, we really like to know if they’re running under virtualization when we try to support them. Here’s some tricks to detect, from
a shell, if the system is virtualized.

The first thing to check is dmesg. On a recently-booted system, checking the
‘dmesg’ command output may be sufficient. Otherwise, try “cat /var/log/dmesg”
instead of “dmesg”

• VMWare:

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  # dmesg | grep -i virtual  VMware vmxnet virtual NIC driver  Vendor: VMware    Model: Virtual disk      Rev: 1.0  hda: VMware Virtual IDE CDROM Drive, ATAPI CD/DVD-ROM drive

• QEmu or KVM:

  If the “-cpu host” option has not been used, QEmu and KVM will identify
  themselves as:

  
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   # dmesg | grep -i virtual
  
   CPU: AMD QEMU Virtual CPU version 0.9.1 stepping 03
  
  

  otherwise, the host’s CPU information will be used both in dmesg, or in
  /proc/cpuinfo.

  However, you should see something like:

  
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   $ dmesg | grep -i virtual
  
   [    0.000000] Booting paravirtualized kernel on KVM
  
  

  on newer kernels that understand that they’re running under paravirtualization.
  (Thanks to René Pfeiffer for pointing this out)

• Microsoft VirtualPC:

  
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   # dmesg | grep -i virtual
  
   hda: Virtual HD, ATA DISK drive
  
   hdc: Virtual CD, ATAPI CD/DVD-ROM drive
  
  

• Xen (thanks, wardi and others)

  
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  # dmesg | grep -i xen
  
  Xen virtual console successfully installed as tty1
  
  

• Virtuozzo

  
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  # dmesg
  
  (returns no output)
  
  
  
  
  
  # cat /var/log/dmesg
  
  (returns no output)
  
  
  
  
  
  # ls -al /proc/vz
  
  veinfo  veinfo_redir  veredir  vestat  vzaquota  vzdata
  
  

On longer-running systems, you may need to grep /var/log/dmesg instead.

If that doesn’t produce anything useful, try using dmidecode to look at the
BIOS information. Frequently, there will be at least one component identifying
itself as virtualized:

• VMWare:

  
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   # dmidecode | egrep -i 'manufacturer|product'
  
   Manufacturer: VMware, Inc.
  
   Product Name: VMware Virtual Platform
  
  

• Microsoft VirtualPC:

  
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   # dmidecode | egrep -i 'manufacturer|product'
  
   Manufacturer: Microsoft Corporation
  
   Product Name: Virtual Machine
  
  

• QEMU or KVM:

  
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   # dmidecode | egrep -i 'vendor'
  
   Vendor: QEMU
  
  

• Virtuozzo:

  
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   # dmidecode
  
   /dev/mem: Permission denied
  
  

• Xen:

  
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   # dmidecode | grep -i domU
  
         Product Name: HVM domU
  
  

You should just examine the output of dmidecode directly rather than trying to
grep as above, in case the output changes. QEMU, for example, doesn’t report
the vendor in all versions.

Next, check disk devices for identification as virtualized:

• VMWare:

  
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  # cat /proc/ide/hd*/model
  
  VMware Virtual IDE CDROM Drive
  
  # cat /proc/scsi/scsi
  
  Attached devices:
  
  Host: scsi0 Channel: 00 Id: 00 Lun: 00
  
    Vendor: VMware   Model: Virtual disk     Rev: 1.0 
  
    Type:   Direct-Access                    ANSI SCSI revision: 02
  
  

• Microsoft VirtualPC:

  
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  # cat /proc/ide/hd*/model
  
  Virtual HD
  
  Virtual CD
  
  

• QEMU, KVM, or Xen:

  
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  # cat /proc/ide/hd*/model
  
  QEMU HARDDISK
  
  QEMU DVD-ROM
  
  

• Virtuozzo:

  
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  # ls -al /dev/vzfs
  
  b-----x--- 1 root root 0, 19 2009-04-06 15:04 /dev/vzfs
  
  

If you’ve got tips for other virtualized environments, let me know and I’ll add
them to the list.