Storage Space level quota considerations

As an administrator, understand how you can define and manage space level quota for volumes and buckets.

Only administrators can define the volume and bucket storage space.
By default, the quota for volume and bucket is not enabled and the size is unrestricted. To enable quota, you need to set quota limits for the volumes and buckets using CLI options.
After you enable the volume quota, the total bucket quota cannot exceed the volume quota.
You can enable the bucket quota without enabling the volume quota. The size of the bucket quota is unrestricted as the volume quota is not set.
Volume quota comes into effect only when the bucket quota is set. You need to set the bucket quota before setting the volume quota for the volume quota to come into effect. This is because Ozone can only check the usedBytes of the bucket when we write the key and volume quota can monitor the bucket for usedBytes.
You cannot disable the bucket quota until you enable the volume quota.
When a volume has linked (for example, symlink) buckets, the linked bucket space usage is not restricted by this volume. Linked bucket space usage is restricted by source volume quota and monitored by source volume and source bucket quota. For example, adding keys and files to the bucket (symlink) linked to the volume does not impact the linked volume.
A quota value with -2 for the volume and buckets represents old volume and buckets where space usage is not captured. The quota feature does not support such volumes and buckets. This needs a recalculation of space usage to support the quota feature during the upgrade. Space usage recalculation is required during the upgrade as enabled by default to rectify incorrect values as the quota feature was not supported previously.