On Mon, Apr 27, 2020 at 3:07 PM antlists <[email protected]> wrote: > > On 27/04/2020 17:59, Rich Freeman wrote: > > Really though a better solution than any of this is for the filesystem > > to be more SSD-aware and just only perform writes on entire erase > > regions at one time. If the drive is told to write blocks 1-32 then > > it can just blindly erase their contents first because it knows > > everything there is getting overwritten anyway. Likewise a filesystem > > could do its own wear-leveling also, especially on something like > > flash where the cost of fragmentation is not high. I'm not sure how > > well either zfs or ext4 perform in these roles. Obviously a solution > > like f2fs designed for flash storage is going to excel here. > > The problem here is "how big is an erase region". I've heard comments > that it is several megs.
I imagine most SSDs aren't that big, though SMR drives probably are that and more. But I agree - for anything like this to work it really needs to be a host-managed solution ideally, or at least one where the vendor has published specs on how to align writes/etc. -- Rich
