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Multicore VM with Linux extremely slow on OS X host

Posted: 21. Nov 2015, 16:39
by dkresan
Hello,

sorry for possibly doubled topic, wanted to bring it up again.

I have MacPro 3.1 with 2 x Intel Xeon (8 physical cores) and 16 GB RAM. Latest firmware is installed.

VirtualBox 5.0.10 with Ubuntu 14.04 VM. 4 Cores and 8 GB RAM were assigned to it, together with switching on virtualisation in VirtualBox. It results in 10 min start-up time, and overall EXTREMELY slow operation. It does not even try to use more than 1 core, and I/O performance is also low. The VBox.log is attached. Any help or hint is appreciated.

Best regards.

Re: Multicore VM with Linux extremely slow on OS X host

Posted: 24. Nov 2015, 09:39
by loukingjr
First you are over-committing RAM
00:00:01.782279 Host RAM: 16384MB total, 8628MB available
00:00:01.915674 RamSize <integer> = 0x0000000201300000 (8 609 857 536, 8 GB)
The general rule of thumb is to set the RAM for the guest to 50% of available memory.
Second, although you have 8 cores, they are spread over 2CPUs.
I would try reducing the number of CPUs to 2 and the RAM to 2GB just to test.

FWIW, your CPUs have reached the EOL. They have no hyperthreading and no EPT. Performance will suffer somewhat.
The guest additions in your guest don't match the VB version.

Code: Select all

00:01:33.061247 VMMDev: Guest Additions information report: Version 5.0.6 r103037 '5.0.6'
You need to update them.

Re: Multicore VM with Linux extremely slow on OS X host

Posted: 24. Nov 2015, 10:03
by michaln
You can't expect miracles from hardware that was discontinued 6 years ago...

Re: Multicore VM with Linux extremely slow on OS X host

Posted: 24. Nov 2015, 10:22
by dkresan
Thank you for explanations. Yes, I agree, the host is already almost 8 years old. It can what it can.

Setting number of CPUs to 2 indeed solves the problem. I will also reduce the amount of RAM allocated.

Thanks and best regards.

Re: Multicore VM with Linux extremely slow on OS X host

Posted: 24. Nov 2015, 10:24
by loukingjr
Welcome. You can probably get away with 4GB or RAM. Try it and see if 2Gb or 4GB makes a difference.