ZFS + FreeBSD + virtualbox

[john2011]

I'm configuring a virtual host providing a few FreeBSD guests running busy email servers. The hardware would be Dell R710 with 6 x 600GB 15K RPM Serial-Attach SCSI 6Gbps 3.5in Hotplug Hard Drive, ie, they are very fast drives.

We used to order Dell H700 RAID controller for RAID6. But I just read many advocates for ZFS. Will ZFS (RAID-Z2) provides any benefit in our case? Seems that people discouraged such usage, see http://serverfault.com/questions/227991/zfs-freebsd-virtualbox

 

[davidgurvich]

ZFS likes raw drives. Virtual drives not so much.

 

[dennylin93]

If you're not using entire disks, you will probably experience a huge drop in I/O. Using ZFS on the host OS and then UFS inside the guests might be better.

 

[john2011]

Maybe my post was not clear, but that is what I wanted to do. That is, the host FreeBSD entirely runs on ZFS. And I thought I then don't need to order RAID controller, so just need to order the six drives. But the guy at http://serverfault.com/questions/227991/zfs-freebsd-virtualbox said I still need to order another controller. Is that true?

 

[danbi]

About ZFS: You will be better with HBA, than with a 'real' RAID controller. If you need to use an RAID controller, create separate volume from each disk (single disk volume) and use these for ZFS. ZFS performs better/faster if it knows the disk topology. Sometimes the difference can be dramatic.

You don't need VirtualBox to run FreeBSD within FreeBSD. Of course, you can -- VirtualBox will provide some useful tricks. But performance wise, especially for I/O and networking, you will be much better using FreeBSD jails for the guests. For most uses, you can use different FreeBSD version guests, although I hardly see how this would matter for a mail server.

Many of the notes you read on ZFS, especially some restrictions are only valid for Solaris.