[SAFS]: store chunks of an SAFS file to disks in random order.
[SAFS]: store chunks of an SAFS file to disks in random order.

This can help improve I/O utilization when accessing multiple files
sequentially.

icoming/FlashX,icoming/FlashX,flashxio/FlashX,icoming/FlashX,zheng-da/FlashX,zheng-da/FlashX,flashxio/FlashX,zheng-da/FlashX,zheng-da/FlashX,zheng-da/FlashX,flashxio/FlashX,flashxio/FlashX,flashxio/FlashX,flashxio/FlashX,icoming/FlashGraph,icoming/FlashX,icoming/FlashGraph,icoming/FlashGraph,icoming/FlashGraph,icoming/FlashGraph,icoming/FlashX