Becuase you don't get more space when adding the flash pool... why isn't is possible to just write any unique data from the flash pool to the spinning rust and then remove it?
Also does it even make any sense to add Flash Pool to a system like the FAS2750 which already have a 1TB NVMe which us also used for read cache? Isn't the Flash Pool also read cache?
...or is there a hidded way to get rid of a flash pool? Not that I would ever do that on an aggregate with important data on it..
#What is the reason why you cannot remove Flash Pool from an aggregate?
shrewd cradle
green tendon
The flash pool is the aggregate. Do you mean to remove the SSD and make it a normal aggr?
static tangle
Probably not enough use-cases? It would need to be developed, tested, etc.
shrewd cradle
The flash pool *is* the aggregate. Do you mean to remove the SSD and make it a n...
Yes you can add SSD disks to an existing aggregate, but you don't get any space bennefit as it is all read cache... but you cannot remove the SSD part again, you need to move the volumes away from the aggregate.... also I found out that flash cache (the NVMe on a FAS2750) is not used if you also use Flash Pool...
oh and I foud a note from NetApp support that the Flash Pool can be disabled with help from support... but apparently not removed... 🙂
static tangle
you can disable it, yeah, just set cloud retrieval policy accordingly but you cannot get rid of it once it is added to an aggregate. neither FlashPool nor FabricPool can
personally I would stay as far away as possible from FlashPool though... We had so much trouble with that in the past where customers got burned by bugs and issues that I cannot really recommend it at all
better get a few more SSDs, create SSD aggregates and do Fabric Pool inside the cluster (or even to another cluster) to a SATA aggregate
oh and you can totally use FlashCache for FlashPool aggregates, it's just that you almost certainly don't gain anything from it and just fill up your flash with useless data... but if you want to do that, you can 😄
timber widget
Yes you can add SSD disks to an existing aggregate, but you don't get any space ...
A Flash Pool (whether whole SSDs or Storage Pool allocation units) is both a read and write cache (by default - you have config options). A Flash Cache is read-only cache.
near cargo
Honestly FlashPool is only good for specific workloads. if you have mostly sequential reads/writes, you won't see a benefit and will burn your disk performance. If you can afford a FlashPool, a C series should be in the same pricerange.