}
			}
		}

		wk.Take()
		go func(setIdx int) {
			defer wk.Give()
			err := set.listObjectsToRebalance(ctx, bucket,
				func(entry metaCacheEntry) {
					wk.Take()
					go rebalanceEntry(entry)
				},
			)
			if err == nil || errors.Is(err, context.Canceled) {
				return
			}
			setN := humanize.Ordinal(setIdx + 1)

	CompleteMultipartUpload(ctx context.Context, bucket, object, uploadID string, uploadedParts []CompletePart, opts ObjectOptions) (objInfo ObjectInfo, err error)

	GetDisks(poolIdx, setIdx int) ([]StorageAPI, error) // return the disks belonging to pool and set.
	SetDriveCounts() []int                              // list of erasure stripe size for each pool in order.

	// Healing operations.