I lack the basic understanding of what segments mean, so we were being limited to 512kib requests even with higher max_sectors sizes set. Setting the maximum number of segments to unlimited allows us to actually have arbitrarily large IO's go through NBD. Signed-off-by: Josef Bacik <jbacik@xxxxxx> --- drivers/block/nbd.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c index 6e592c2..76e5f8f 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -1470,6 +1470,7 @@ static int nbd_dev_add(int index) disk->queue->limits.discard_granularity = 512; blk_queue_max_discard_sectors(disk->queue, UINT_MAX); blk_queue_max_segment_size(disk->queue, UINT_MAX); + blk_queue_max_segments(disk->queue, USHRT_MAX); blk_queue_max_hw_sectors(disk->queue, 65536); disk->queue->limits.max_sectors = 256; -- 2.7.4