I have seen this before in older ONTAP and thought it had been fixed...but maybe it was never considered a BURT since an easy workaround...but we just noticed this behavior in ONTAP 8.0.1 GA.
1. Customer has existing 1TB SATA drives in aggregates with 2 spares.
2. They add 42x 2TB drives. There now have 2x 1TB spares and 42x 2TB spares.
3. They create an aggregate of 20x 2TB Drives to create archive volumes. "aggr create aggrname -r 20 20"
4. ONTAP chooses the two 2x 1TB and 18x 2TB disks for the aggr…leaving all 2TB spares. The aggregate had a mix of 1/2TB disks and no 1TB spares for existing aggregates. So now the 1TB aggregates have to spare and right size 2TB drives to 1TB...and not an optimal layout for the new aggregate.
An easy fix...We destroyed the aggregate and used the syntax "aggr create aggrname -r 20 20@1655" to force all the same drive size in each aggregate with spares of each drive size available. Luckily this was a new aggregate, not an add to an existing aggregate...not a typical PSE issue since most use "-d x.xx.xx" or "@size" in the syntax...or for System Manager they could choose drive size..but for average users on the CLI, it would be nice if ONTAP would choose all the same drive size knowing only that many of that drive size are available.... especially when it has 42x 2TB to choose from..instead of assuming mixing drive sizes. Not a big deal, but one that could cause a lot of hassle since users/customers may get themselves into mixed drive size aggregates with this behavior...and the only way to fix it is to migrate the data and destroy the mixed drive aggregate.
Anyone else notice this behavior or have issues with it? Again, not a show stopper but have to be careful if customers use the CLI to create aggregates and they have mixed drive sizes.
