If you do not care about this NFS problem (or the others) then maybe
you can just disable the ZIL. It is a matter of working through step
1. Working through STEP 1 might be ``doesn't affect us. Disable
ZIL.'' Or it might be ``get slog with supercap''. STEP 1 will never
be ``plug in OCZ Vertex cheaposlog that ignores cacheflush'' if you
are doing it right. And Step 2 has nothing to do with anything yet
until we finish STEP 1 and the insane failure cases.
AFAIK OCZ Vertex 2 does not use volatile DRAM cache but non-volatile
NAND grid. Whether it respects or ignores the cache flush seems irrelevant.
There has been previous discussion about this:
http://comments.gmane.org/gmane.os.solaris.opensolaris.zfs/35702
"I'm pretty sure that all SandForce-based SSDs don't use DRAM as their
cache, but take a hunk of flash to use as scratch space instead. Which
means that they'll be OK for ZIL use."
Also:
http://www.techspot.com/news/37729-ocz-vertex-2-pro-100gb-ssd-review.html
"Another benefit of SandForce's architecture is that the SSD keeps
information on the NAND grid and removes the need for a separate cache
buffer DRAM module. The result is a faster transaction, albeit at the
expense of total storage capacity."
"So if I interpret them correctly, what they chose to do with the
current incarnation of the architecture is actually reserve some of the
primary memory capacity for I/O transaction management."
"In plain English, if the system gets interrupted either by power or by
a crash, when it initializes the next time, it can read from its
transaction space and "resume" where it left off. This makes it durable."
So, OCZ Vertex 2 seems to be a good choice for ZIL.
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