On some Linux installations, a sufficiently large amount of local disk activity can slow down process scheduling. This can cause other operations (e.g., network communication and instance provisioning) appear to stall. Examples of disk-intensive operations include preparing disk images for launch and creating ephemeral storage.
CONCURRENT_DISK_OPS
parameter to the number of disk-intensive operations you want the NC to perform at once.
CONCURRENT_DISK_OPS
to 1 to serialize all disk-intensive operations. Or …