On 02/07/2018 09:15 AM, Ravi Prakash Putchala wrote: > We would like to experiment and see the performance results with different options of dm-crypt. To do this we would like to setup /dev/zero with dm-crypt as mentioned in https://www.redhat.com/archives/dm-devel/2015-February/msg00106.html > However, when I did the following no new mapping gets created in /dev/mapper: > > # cryptsetup -y luksFormat /dev/zero This command cannot work, /dev/zero is a character device, moreover all writes there are discarded. Seems cryptsetup does not print error message here (that is a bug) but return value of this command indicates the problem: 4 - that means "wrong device specified" (see man page). If you need experiment over a memory device, use either ramdisk, scsi_debug module to it. Another alternative is to create dm-zero device and use plain dm-crypt (not LUKS). Milan -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
