virtualbox.org

Got VirtualBox 5.2.6 64 bit running on a reasonably powerful machine (8 core 64GB RAM, 512GB SSD AMD Ryzen)

Trying to move an old database server onto a guest VM (running Debian 9 64 bit with Sybase SQLAnywhere 10)

It seems that the host is reasonably fast on the disk side of things (about twice as fast as the old bare metal machine)

However, doing a database backup (which is all local, no network traffic) is going very slowly - about 15 times more slowly.

Looking at the processes involved, I get the feeling that VirtualBox is not giving as much CPU & memory to the db server/guest OS as it might. Not sure that memory is the issue - but it must be bound by something.

The guest is showing 75% CPU in "top", and I said that it could have 4 CPUs, with 100% execution cap and Enabled PAS/NX (whatever that is!). Also enabled is I/O APIC, but not EFI.

The host is showing around 100%-125% CPU.

Any advice for other settings? Should it make any difference if I say it's IDE/SATA/SCSI/SAS?

I believe guest additions are installed.

Any suggestions on how to tweak this?

Please post a VM log file. With the VM fully shut down, right click and "Show Log" in the GUI, save "VBox.log" (no other file) to a zip, and attach the zip here.

OK - here it is...

Something crazy seems to be going on with the display, it seems to be getting constant resize events and not resizing. And I notice that you're running the buggy GAs - you should have a read of the Discuss the 5.2.6 Release topic, and give the 5.2.7 GAs a try.

mpack wrote:Something crazy seems to be going on with the display, it seems to be getting constant resize events and not resizing.

I saw them... Ay caramba!

A couple of things that could be the source for so many messages:

00:00:00.076891 VRamSize <integer> = 0x0000000001000000 (16 777 216, 16 MB)

That seems too low. Maybe taking it to 32 or 64 MB would be much better. It's not like there's a memory shortage...

03:07:31.178223 VRDP: New connection: 
03:07:31.178246 VRDP: Connection opened (IPv4): 1

The guest is accessed via VRDP, I really don't know what that does to the display warnings. Encourages them?

Good catch on the VRAM.

Mmm. Not sure if the VRAM thing is relevant, but well spotted!

I've been doing some other tests, and I don't think this has anything to do with virtualisation - it runs very slowly, even on the bare metal of the host in question. Which is really odd, as it's supposed to be a really fast machine!

So I'm wondering if I've stumbled across a use-case where SSD is slower than spinny HDD's or maybe that Debian 9 is slower than Ubuntu 12.04 for this application....

alexlake wrote:for this application....

I'd start with that part...