On 9/22/19 9:42 AM, Luse, Paul E wrote:
Still just a POC and a lot of work to do before we'd consider
production worthy> if we decide to continue with it (I'll work on putting a list
together over the next few weeks).
Are any of the Linux kernel RAID implementations considered good?
I have DRBD 9.0 running in usermode under SPDK as shown in this diagram:
One possibility would be to port a kernel RAID module into the spot occupied by DRBD in
The "port" of DRBD to run in usermode changes fewer than a dozen lines of code
from the original source in the LINBIT repository. Rather than changing the source code
from the DRBD kernel module, its expected environment is simulated around it. (This is
intended to make it easier to update the usermode port to newer versions of the
application as they appear.)
I did the same thing with SCST a couple of years ago. I would expect the same to be
possible for a kernel RAID module. It won't just "drop in", because the set
of emulated kernel functions has to be expanded to include whatever the RAID module uses
that isn't already covered by the existing ports of SCST and DRBD. I estimate it
would take me one to two months of full-time work to get a kernel RAID module up and
running well enough to be tested and used for experimentation.