What is the recommendation for the maximum number of discs in a storage pool? I want to create a large RAID1+0 storage pool. Is one pool with 20 discs OK, or should I split it into two pools of 10 discs?
The "Best Practices for Performance" document just says make sure the number of discs is suitable for the RAID type you're using. (Among other things)
From a performance perspective both is fine
Decision points there are more around functionality, space reserveration and failure domain – that should be discussed in the BPP
For example if you plan to use deduplication I would suggest two pools
If there is a sweet-spot, or maximum recommendation it is certainly much higher than even 20 disks...
So I would agree that your configuration and usage/workload is much more important.
Is this a single enclosure 25 disk unit with only one drive type?
From the VNX2 Virtual Provisioning White Paper (P/N H12204.6, March 2016) at https://support.emc.com/docu48706_Virtual-Provisioning-for-the-VNX2-Series---Applied-Technology.pdf
Max Disks Per Pool by VNX Array Model:
Do read the white paper, though, as there are some caveats. This discussion starts around page 14.
These are the max numbers (max total drives – 4) – not necessarily the recommended size
Agreed. That's why I included the caveat to read the specific section of the whitepaper.
Note, the original question (emphasis added by me) was:
What is the recommendation for the maximum number of discs in a storage pool?