Flash Pool with a total of 4 SSD

Hi,

we buy a new FAS2720 with 4 SSD and 8 HDD and 3 DS212C with 12 HDD each, for a total of 4 SSD 960GB and 44 HDD 4TB.

Now I'm configuring Flash Pool, like the old FAS2554 (4 SSD + 20 HDD) that will be migrated on the new FAS.

So I use the same command use some years ago on the 2554:

storage aggregate modify -aggregate cluster4_01_NL_SAS_1 -hybrid-enabled true

storage pool create -storage-pool StoragePool_c4_Cache1 -disk-list 1.0.0,1.0.10,1.0.1

now

storage aggregate show-spare-disks -disk-type SSD

show one disk as spare on node02 (the same as 2554).

But when I try to add flash-pool to aggregate I have this error:

storage aggregate add cluster4_01_NL_SAS_1 -storage-pool StoragePool_c4_Cache1 -allocation-units 4 -raidtype raid4

Error: command failed: storage pool "StoragePool_c4_Cache1" does not have enough spare allocation units. Use "storage pool show-available-capacity" to get the spare allocation units assigned to node cluster4-01.

 So, what is changed on FAS2720 and/or ONTAP 9.9.1? I remember that in the past an SSD spare can be shared from node.

Now I'm in difficulty if I cannot create my flash pool.

Thanks