Hi, I am checking dmraid functionality for RAID5 with 3 disks. I am using the latest available patch on http://people.redhat.com/heinzm/sw/dm/dm-raid45/ I have some confusion in the same. The target length in the function raid_ctr in dm-raid4-5.c is being displayed to me as the smallest disk sectors. However, I understand that the target length should be the total sectors (of all available disks) available for data (which in my case should be 2 disk sectors since 1 disk sectors would be utilized for parity) What I understand is, in the user level dmraid, in lib/activate/activate.c, under dm_raid45, sectors value is calculated by: Sectors = _smallest(lc,rs,0) And, the same sectors value is passed to _dm_raid45_bol. Whatever goes from this _dm_raid45_bol directly goes to the kernel dm-raid4-5.c and under raid_ctr gets printed as ti->len right? So, the smallest sectors (of all the devices) goes to ti->len. In my case also, the smallest disk sectors is being printed as ti->len and not the total data sectors. Am I wrong? Also, I had another doubt in dm-raid4-5.c, under static struct raid_type raid_types[], values for raid5_ls is: {Raid5_ls. "RAID5 (left symmetric), 1, 3, raid5, left_sym}, where the number of parity devices (being the 3rd parameter) is taken as 1. But, I feel, since there isn't any dedicated parity device for RAID5, shouldn't this be taken as 0. When I take this as 1, I am getting the error, target length not divisable by number of devices. When I take it as 0, my RAID volume is being created and things seem to work. Any suggestions would be helpful Thanks Vidya -- dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
