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From: "John Levine" <johnl@iecc.com>
To: freebsd-questions@freebsd.org
Cc: wallbridge@blur.com
Subject: Re: ZFS for raid
In-Reply-To: <CAP=GgsSaGqkBhdC85+9yrDoUPTR8CXAECKq5D1T67O9Q3A8g2g@mail.gmail.com>
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In article <CAP=GgsSaGqkBhdC85+9yrDoUPTR8CXAECKq5D1T67O9Q3A8g2g@mail.gmail.com> you write:
>You do _not_ want a hardware raid controller if you are running ZFS. You
>can set up ZFS for your boot drives during setup, not 100% sure about
>another file system, but their is really no need as you can set it up once
>you are up and running.

Correct.  ZFS does the RAID stuff so you do not want the controller helping.

ZFS can do mirrors, n/m RAID and just about any combination you can
imagine.  Recent versions of FreeBSD can boot from ZFS, but it's fine
to combine ZFS and UFS on the same system.

On my home server, the boot disk is a little UFS SSD, with an external
four-disk ZFS RAID I use for backups.  My real server has four disks
arranged as two pairs of mirrors in one bootable filesystem.

This is all explained reasonably well in the FreeBSD handbook and the
man pages.