Comment by londons_explore
4 years ago
To emulate a flushing SSD, the signal really needs to go directly to the SSD firmware so it can decide which is the last OS write it can accept while still having enough power to persist all write and flush requests it has already accepted.
Getting all that right sounds so hard it is probably better to just have enterprise SSD's have a built in supercap to give 5 seconds or so of power to do all the necessary flushing, and for laptop/desktop grade SSD's they only need to offer barriers for data consistency. Laptop and desktop users don't care if they lose the last 1 second of data before a crash as long as what is on the drive is self consistent.
I should've been a little clearer; by "enterprise systems" I was referring to RAID controllers and the like. Though yes, I believe enterprise SSDs/NVMes likely have a capacitor or, as one friend put it, an "overkill battery" to use for flushing data.
To be fair though, I sidetracked from the discussion at hand. The issue Marcan described was regarding the OS -> Disk rather than a "power loss situation". The latter does play in with the former, but solving the latter doesn't necessarily solve the former.