Crazy ZFS ZIL options: md(4) umass(4)

[Xin LI]

On Fri, Feb 15, 2013 at 1:00 AM, grarpamp <grarpamp at gmail.com> wrote:
> I have thousands of small files being written most under 8KiB, they
> either end up being removed or combined in various ways to
> produce a set of data that is stored long term. I also have
> tens of 10-50MiB files similarly, but rarely. It's not fully clear
> to me the benefits of a split ZIL. Some say a split ZIL will ward
> off some fragmentation, which pushing over 80% I'm sure to see
> otherwise. Plus a speed boost if on faster media. And maybe
> even no need to commit some ZIL to disk as small files are
> removed before ZFS decides to aggregate?
>
> Anyway, use case aside, I can put 1GiB of ram as ZIL.Same for 32GiB USB.
> RAM is obviously fast and power fail prone.
> USB is slow and power safe.
> Either could be mirrored, 2xRAM, 2xUSB.
>
> - If I lose power on RAM, will the disk still be consistent?
> - What data integrity does ZIL have? None? ZFS dataset's sha256?
> - Any production experiences with this crazy ideas?

Why don't just set sync=disabled?

Cheers,
--
Xin LI <delphij at delphij.net> https://www.delphij.net/
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