# ZFS + FreeBSD + virtualbox



## john2011 (Jan 28, 2011)

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


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## davidgurvich (Jan 29, 2011)

ZFS likes raw drives.  Virtual drives not so much.


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## dennylin93 (Jan 29, 2011)

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.


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## john2011 (Jan 29, 2011)

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?


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## danbi (Jan 29, 2011)

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.


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