Best practices is on lun wizard in VSC when you provision datastor or on SystemManager 2.0 when you ceate LUN.
My best practices.
Turn off snap reserve on volume (snap reserve 0) when you use snapshots on LUN System dont use that space. For snapshots on the lun system use volume free space.
Example vlume have 100gb Lun have 70gb space for snapshots is 30 gb on volume.
Fractional reserve example
Fractional reserve 100%
Lun have 20 WAFL BLOKS
VOLUME have 40 WAFL BLOCKs
When you create snapshot on datastore on 10 WAFL blocks system reserve 10 bloks in free space on volume
When you create secound snapshot on 10 (from the first snapshot) and 4 new block snapshot fractional reserve allocate 4 blocks on free volume space
Fractional reserve 20% CLI option
Lun have 20 WAFL BLOKS
VOLUME have 40 WAFL BLOCKs
When you create snapshot on datastore on 10 WAFL blocks system reserve 2 bloks in free space on volume
When you create secound snapshot on 10 (from the first snapshot) and 4 new block snapshot fractional reserve allocate 2 blocks on free volume space
If you use deduplication or snapshot you must check:
1. Alghin on datastore mbralghin tool
2. Tur on thin provisioning on lun on volume it is optional but in this case turn on it.
3. Check snapshots delete all unused unneeded snapshots.
For snapshot on Vmware use VSC.
I dont understand why youre volume grow so dramaticli, how many space you have ? Why you do not use tryfirst option or autogrow option?