On 03/01/2016 03:43 PM, Bart Van Assche wrote:
After having run multipath -f + another reconfigure I noticed that the optimal_io_size parameter for multipath devices is zero (io_opt) but that blk_stack_limits() expects that that parameter is not zero. So i tried to repeat the test described in commit e9637415a92cf25ad800b7fdeddcd30cce7b44ab: # modprobe scsi_debug dev_size_mb=10 num_tgts=1 opt_blks=1536 # lsscsi | grep debug [17352:0:0:0]disk Linux scsi_debug 0184 /dev/sds # cat /sys/block/sds/queue/optimal_io_size 1536 # dmsetup create node --table "0 100 linear /dev/sds 0" (hangs in the semop() system call) ^C
(again replying to my own e-mail) Apparently this works fine with kernel v4.5-rc6: # modprobe scsi_debug dev_size_mb=10 num_tgts=1 opt_blks=1536 # lsscsi | grep debug [42:0:0:0] disk Linux scsi_debug 0184 /dev/sdai # cat /sys/block/sdai/queue/optimal_io_size 786432 # dmsetup create node --table "0 100 linear /dev/sdai 0" # dmsetup table | grep linear node: 0 100 linear 66:32 0 # dmsetup ls | grep node node (254:2) # cat /sys/block/dm-2/queue/optimal_io_size 786432 I will report this to the proper bugzilla. Sorry for the noise. Bart. -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
