On 09/16/2013 03:47 PM, Francis Moreau wrote: [...] >>>> Wrt loop1[2], I think you interpret the [2] wrongly. It seems to be the >>>> kernel index of the device somehow. The mdstat parsing code of mdadm >>>> doesn't look at this number. If you look at >>>> /sys/class/block/md124/md/dev-loop*/slot, the number should be correct - >>>> I tried it here. >>> >>> Well I think I interpreted the numbers the way it's described here : >>> >>> https://raid.wiki.kernel.org/index.php/Mdstat#md_device_line >> >> That description is not quite correct. The number in brackets [2] means >> the index of the disk in the meta data (for DDF, that's the index in the >> "physical disks" table of the container). That number isn't very >> meaningful except for the meta data itself. >> >> The logical disk index is represented by the "slot" attribute in sysfs. >> >> See e.g. >> http://lxr.missinglinkelectronics.com/linux+*/drivers/md/md.h#L79 >> >> The number displayed in /proc/mdstat is "desc_nr", while the number that >> actually matters is "raid_disk". > > Maybe the description in the wiki is correct but there's a bun in the > kernel which displays the wrong number ? > > If "desc_nr" isn't meaningful, I don't see the point to show it in > /proc/mdstat. Well, we could propose to change the value displayed by the kernel. The question is whether the kernel maintainers would allow that, because it would change the kernel-userspace API. mdadm itself doesn't look at this number, but other tools might, so there is some small but non-zero risk of breaking something somewhere. Let's wait what others have to say. Martin -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
