>> 2. A metadata handler needs build metadata based on several data such as >> raid set name, raid level, size, etc. Can they be carried into as a >> string argument or a field in "struct lib_context"? It's possible to >> build disk sets, raid device sets, and raid set sets too. > >No, a create_set() function needs adding to the library, which can >be called with a struct holding the respective parameters and lists of >devices involved. > >That function will derive properties of raid_dev arguments >for the metadata format handler .create method. > >commands.[ch] need the respective extensions to support >the "-C/--create" command line option. > >> 3. Can I design my own option format to create metadata by DMRAID such >> as:"dmraid -ms isw_xxxxxx_raidSet1" (d and D have been used.) to delete >> a raid set and "dmraid -f isw -w "isw_xxxx_raidNewSet device-mapper >> format" where device-mapper format is "0 1028160 striped 2 256 /dev/sdb >> 0 /dev/sdc 0". But I have trouble for nested raid setup and try to use >> raid10 or raid51 to identify it. > >To create a RAID set: >dmraid -C isw_xxxxxx_raidSet1 [--layout LAYOUT] [--size X[kmgt]] >[DevicePath...] > >LAYOUT = string types defined in metadata.c (see get_type() function; >eg. "mirror"). >X = size in KB, MB, GB, TB. > >In the isw case, which is different from most other metadata format >handlers >but DDF1, isw.c's create method would need to cover more complex >allocation, >because other volumes might already be on the devices. > >To delete a specific RAID set we can add to the existing erase option: > >dmraid -rE isw_xxxxxx_raidSet1 > Let me rephrase what you've said. The input of DMRAID includes all necessary attributes of a raid set (called volume in ISW) to be created. An internal function, create_set, grabs user's choices and fills into a data structure, e.g. struct raidset_attr. Then it calls .create of an appropriate handler to build and write metadata to each hard device of the raid set. Also struct raidset_attr should cover parameters used to setup spare devices, resize an old raid set, and migrate non-raid device to a raid set, etc. How about manual and auto rebuilding? Should updating metadata status be handled by DMRAID or device drivers? Thanks, Ying _______________________________________________ Ataraid-list mailing list Ataraid-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/ataraid-list
