2014-01-06 03:45 AM
Just looking for peoples opinion on the following disk configuration for a new install.
Assign 9 disk to controller A create raiddp aggr
aggr0 - 8 (6data-2 parity) 1 spare
assign 3 disk controller B create raid4 aggr
aggr0- 2 disk (1data-1 parity) 1 spare
Looking to maximse disk space whilst still keeping it fairly best practice.
2014-01-09 05:54 AM
So basically the second filer is a hot standby?
We made a large storage purchase and NetApp "threw in" three "free" FAS2220 12-disk pairs. With 12 disks for a pair of filers, they're basically next to useless. By the time you take out two disks for spares, 4 disks for dp parity, you are left with 6 data disks (7 if you do raid-4 on one head like above). We thought long and hard about how to distribute the disks, and we settled on evenly distributing them between the two controllers, so as to be able to take advantage of the processing power of each filer. 6 disks on each filer: 1 spare, 5 disk raid-dp aggr0. We shrunk vol0 as much as we could to free up more space.
As much as we hate wasting disks with raid-dp, it makes upgrading firmware non-disruptive and that's why we use raid-dp everywhere.
2014-01-09 06:05 AM
Yes basically controller2 is a hot standby.
I think we've settled on
8 Disks on controller1 5 Data 2 Parity and 1 Spare
4 Disks on controller2 1 Data 2 Parity and 1 Spare
The main reason is the non disruptive firmware like you mentioned