We have a FAS3250 with 3 aggregates - one with SAS disks, one with 2TB SATA and one with 4TB SATA. Percentage wise they are showing 86% to 96% used. Is there a best practice for the maximum that should be allocated?
Here's part of OnCommand screenshot showing the details.
It is recommended to keep a minimum of 3 % of space kept free on the aggregate . Which means that the aggregate should not be used more that 97% ever.
Personally I would recomend the aggregate is not used more that 95% . The extra 2% will come in handy if all your aggregate / volume space is used .
Yes you can resize the volume down later if necessary without any interuptions provided there is space unused in the volume. For example you have a 100G volume which has used 60G already . You can now resize the volume down upto 60G , Please note that the volume used space becomes 100% now and run out of space. so you may want to resize to 70G or 80G depending upon your need to get the space back to aggregate .
Netapp recomends to grow ( add disks) your aggregate when the utilization approach 80% - 85 % for better performance.