>> You should definitely determine the right value for ashift on pool >> creation >> (it controls the alignment on the medium). It's an option that you afaik >> can only set >> on filesystem creation and therefore needs a restart from scratch if you >> get it >> wrong. >> According to the illumos wiki it's possible to run a mixed pool (if you >> have >> drives requiring different alignments[1]) >> If in doubt: ask ryao (iirc given the right information he can tell you >> which >> are the right options for you if you can't deduce it yourself). >> Choosing the wrong alignment can cause severe performance loss (that's not >> a ZFS issue but happened when 4k sector drives appeared and tools like >> fdisk >> weren't aware of this). > > Yikes... > > Ok, shouldn't there be a tool or tools to help with this? Ie, boot up on a > bootable tools disk on the system with all drives connected, then let it > 'analyze' your system, maybe ask you some questions (ie, how you will be > configuring the drives/RAID, etc), then spit out an optimized config for > you?
I'm also interested to know the procedure for getting this right. > It is starting to sound like you need to be a dang engineer just to use > ZFS... I thought the SSD issue was completely separate from ZFS and applicable to any other filesystem as well. Someone please correct me if I'm wrong. - Grant
