2012-07-25 10:52 AM
I am going to implement FAS 3270 HA pair with four disk shelves and with two types of disks (48 x 600 SAS, 36 x 2 TB SATA) and my plan is to do the configuration based on the below table.
Host Name Aggregate Name RAID Disk Type No Data Disk No of Parity Disk No of Spare Disk
Filer-A Aggr0 RAID-DP SAS 20 2 2
Filer-A Aggr1 RAID-DP SATA 14 2 2
The same configuration will be applied for the HA Pair also.My design was based on considering the below points.
If anyone is having better idea please advice.
2012-07-25 12:07 PM
I would distribute the disks differently, I would put all of the SAS on one controller and the SATA on the 2nd controller, this will allow all of the disks to contribute to the IO needs of the aggregate, in your configuration you would have 2 aggregates for each disk type using only half of the available IO.
2012-07-25 01:00 PM
Hi Michaell ,
Based on your recommendation if i dedicate one controllerfor SAS and another for SATA what will happen if one controller fails? Whether it can take over to the other controller or the IOs will be terminated?
2012-07-25 01:11 PM
Hi Johny, you will not lose any I/O during a failover, Netapp has very clever HA logic. When both controllers are running it is essentially like having 2 systems, each with their own memory, drives, networking, etc. When an event that triggers a failover to occur, the remaining controller has the ability to takeover the drives and logical structures (aggregates, volumes, etc) and it will them mimic the failed controller. Normally this transfer happens with very few lost pings, and well within any I/O timeouts of a guest OS. When running in failover mode the failed controllers IP's, name, and data area all served through the single controller, so there is a possibility for degraded performance IF you happen to be really pushing the system, but hopefully your reseller has sized your unit properly and this is not an issue. Always test HA before putting the system into production, and have qualified engineer verify the shelves are cabled correctly for mulitpath HA.
2012-07-25 01:23 PM
Hi Johny John:
this also depends on the protocols you are going to use along with aggregate layout. As said by somebody, have the sata on one controller and sas on other cluster pair.