On Sep 19, 2013, at 11:25 AM, Guy Helmer <guy.hel...@gmail.com> wrote:
> Normally I build VMware ESXi servers with enterprise-class WD SATA drives and > I/O performance in FreeBSD VMs on the servers is fine. > Whenever I build a VMware ESXi server with a RAID controller, IO performance > is awful in FreeBSD VMs. I've previously seen this effect with VMware ESXi > 3ware 9690SA-8I and 9650 RAID controllers, and now I'm seeing similar > performance with a Dell 6/iR controller. > > Any suggestions would be appreciated. > > Guy (Replying to self due to hint received off-list) I seem to remember controllers mentioned previously by FreeBSD device driver developers that don't deal well with large I/O requests. It turns out that may be the case with VMware device drivers as well -- reducing the VMware Disk.DiskMaxIOSize value from its huge default of 32676KB to 32KB seems to have helped. Disk ops/sec in the FreeBSD VM are now peaking over 400/sec. Guy
signature.asc
Description: Message signed with OpenPGP using GPGMail
