There are no tiers by default.  The upgrade will just convert the existing disk pools into the new nomenclature of node pools.  The file policies will be migrated and will target the new node pools.  If you want to create a tier, you would have to do that after the upgrade and modify your file pool policies to reflect the new target.
Hi everyone,  We have a cluster with ~60 nodes of 4 different types (S200, X200, 10000X-SSD, 72NL), containing about 970T of data. Total size is ~1.5P, with 18.3T of SSD (of which 2T is used). We have 4 existing disk pools, 1 for each type of node, with a 4 file pool rules. It is currently running OneFS 6.5.5.15.   Does anyone have experience upgrading a cluster of around this size and/or complexity to OneFS 7? Any tips on how long it might take to do the restripe, or info on how the disk pools/file pools will fall out under 7?   Thanks! --Ken
Restripe time on upgrade to OneFS 7?