MinIO places new objects in server pools based on proportionate free space, per pool. Following pseudo code demonstrates this behavior.

```go
func getAvailablePoolIdx(ctx context.Context) int {
        serverPools := z.getServerPoolsAvailableSpace(ctx)
        total := serverPools.TotalAvailable()
        // choose when we reach this many
        choose := rand.Uint64() % total

	}
	return
}

func (z *erasureServerPools) listAndSave(ctx context.Context, o *listPathOptions) (entries metaCacheEntriesSorted, err error) {
	// Use ID as the object name...
	o.pool = z.getAvailablePoolIdx(ctx, minioMetaBucket, o.ID, 10<<20)
	if o.pool < 0 {
		// No space or similar, don't persist the listing.
		o.pool = 0
		o.Create = false
		o.ID = ""
		o.Transient = true
		return entries, errDiskFull

		if z.Available > 0 && z.MaxUsedPct < max {
			continue
		}
		p[i].Available = 0
	}
}

// getAvailablePoolIdx will return an index that can hold size bytes.
// -1 is returned if no serverPools have available space for the size given.
func (z *erasureServerPools) getAvailablePoolIdx(ctx context.Context, bucket, object string, size int64) int {
	serverPools := z.getServerPoolsAvailableSpace(ctx, bucket, object, size)