On Tue, 31 Jan 2012, Thomas Nau wrote:
We have two JBODs with 20 or 21 drives available per JBOD hooked up
to a server. We are considering the following setups:
RAIDZ2 made of 4 drives
RAIDZ2 made of 6 drives
The first option "wastes" more disk space but can survive a JBOD failure
whereas the second is more space effective but the system goes down when
a JBOD goes down. Each of the JBOD comes with dual controllers, redundant
fans and power supplies so do I need to be paranoid and use option #1?
Of course it also gives us more IOPs but high end logging devices should take
care of that
I think that the answer depends on the impact to your business if data
is temporarily not available. If your business can not survive data
being temporarily not available (for hours or even a week) then the
more conserative approach may be warranted.
If you have a service contract which assures that a service tech will
show up quickly with replacement hardware in hand, then this may also
influence the decision which should be made.
Another consideration is that since these JBODs connect to a server,
the data will also be unavailable when the server is down. The server
being down may in fact be a more significant factor than a JBOD being
GraphicsMagick Maintainer, http://www.GraphicsMagick.org/
zfs-discuss mailing list