Goswin von Brederlow wrote: > Micha³ Przy³uski <mikylie@xxxxxxxxx> writes: > > > The point was not to add redundancy but to remove complexity. > > Just look at what you need to do for the next generation of disks > (>2TB): > > - Create a MS Dos partition table with a fake /boot partition in the > first 2TB. > - Create a GPT table with a matching /boot partition and the rest > - Create a raid1 for /boot > - Create a raidX for the rest > > Now you have to watch 2 raids and add/remove partitions from 2 raids, > You also need to copy the bootloader to every new disk you add. > > The idea is to bring this down to: > > - Create raidX over all disks > >> it a hidden raid1 over first few sectors is just creating an >> automation that gains nothing and makes things unnecessarily >> complicated inside. > > If the hidden raid1 is just reserved space that is considered part of > the raid metadata then this moves completly into mdadm userspace. The > extra complexity comes down to "read reserved space from old disk, > write reserved space to new disk". In the most basic form that is 3 > lines of code (declare buffer, read, write). > This is the best description of the problem/benefit so far. Also when deciding on the size of the reserved space, factor in possible bitmap size explosion when moving from say a 4x300G raid6 to a 4x2T raid6. +1 on this feature request Cheers -- 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
