On Monday, July 1, 2019 10:09:35 PM CEST John Stoffel wrote: > >>>>> "Mariusz" == Mariusz Dabrowski <mariusz.dabrowski@xxxxxxxxx> writes: > Mariusz> Added new type of line to mdadm.conf which allows to specify > Mariusz> values of sysfs attributes for MD devices that should be > Mariusz> loaded after assemblation. Each line is interpreted as list > Mariusz> of structures containing sysname of MD device (md126 etc.) > Mariusz> and list of sysfs attributes and their values. > > So what does this buy us? Looking at your example, you hard code > devices to a raid name, but also include a UUID setting. Don't you > think that's a bad idea? The UUID and name are two ways to identify the device. In my examples, I have placed the UUID for the first device and the name for the second device. > > > > Mariusz> +.TP > Mariusz> +.B SYSFS > Mariusz> +The SYSFS line lists custom values of MD device's sysfs attributes > which will be Mariusz> +stored in sysfs after assemblation. Multiple lines > are allowed and each line has > > This should be "after assembly." Or maybe "after the array is > assembled." instead. > > Mariusz> +to contain uuid or name of the device to which it relates. > > ... "contain the uuid" ... > > Mariusz> +.RS 4 > Mariusz> +.TP > Mariusz> +.B uuid= > Mariusz> +hexadecimal identifier of MD device. This must match the uuid > stored in the Mariusz> +superblock. > Mariusz> +.TP > Mariusz> +.B name= > Mariusz> +name of the MD device as was given to > Mariusz> +.I mdadm > Mariusz> +when the array was created. It will be ignored if > Mariusz> +.B uuid > Mariusz> +is not empty. > Mariusz> +.TP > Mariusz> +.RS 7 > Mariusz> + > Mariusz> .SH EXAMPLE > Mariusz> DEVICE /dev/sd[bcdjkl]1 > Mariusz> .br > Mariusz> @@ -657,6 +677,11 @@ CREATE group=system mode=0640 auto=part\-8 > Mariusz> HOMEHOST <system> > Mariusz> .br > Mariusz> AUTO +1.x homehost \-all > Mariusz> +.br > Mariusz> +SYSFS name=/dev/md/raid5 group_thread_cnt=4 sync_speed_max=1000000 > Mariusz> +.br > Mariusz> +SYSFS uuid=bead5eb6:31c17a27:da120ba2:7dfda40d group_thread_cnt=4 > Mariusz> +sync_speed_max=1000000 > > So according to the docs above, since you have a SYSFS uuid=... entry, > won't the name be ignored? The name will be ignored if it is given next to uuid in the same entry, for example: SYSFS uuid=bead5eb6:31c17a27:da120ba2:7dfda40d name=/dev/md/raid group_thread_cnt=4 > > Also, it's not clear if the case of these SYSFS atttribures matters or > not. I'd *hope* they don't, because I can see people putting in > > "SYSFS UUID=... " > > Just like the regular ARRAY /dev/md3 UUID=... stuff in mdadm.conf > already. Case of UUID= and NAME= doesn't matter, but sysfs attribute name like "group_thread_count" have to be given in the same form as it is present in / sys/block/mdX/md/. > > Cheers, > John Regards, Mariusz
