Re:Don’t Be Afraid of RAID
by magicalhippo on Sunday May 24, 2020 @08:45PM
(#23296460)
From what I can gather that will not change the fact that the space is determined by the smallest disk in the vdev.
However watching his presentation about RAID-Z expansion I couldn't shake the feeling that that is a rather arbitrary decision. I mean, if you take his slide visualizing the reflow, it seems that as long as you can put the data + parity blocks on different devices, the size of each device in the vdev could be different.
Of course if you only write full stripes (ie one block for each disk) then you would still be limited by the smallest disk, however the beauty is that you can write shorter stripes. So couldn't ZFS just spread those blocks out?
Though it's late, so maybe I missed something obvious here :)
However watching his presentation about RAID-Z expansion I couldn't shake the feeling that that is a rather arbitrary decision. I mean, if you take his slide visualizing the reflow, it seems that as long as you can put the data + parity blocks on different devices, the size of each device in the vdev could be different.
Of course if you only write full stripes (ie one block for each disk) then you would still be limited by the smallest disk, however the beauty is that you can write shorter stripes. So couldn't ZFS just spread those blocks out?
Though it's late, so maybe I missed something obvious here :)