Scott - ZFS Mirror with SLOG

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Hi guys,

long-time asynchronous listener, first time questioner.

In your last episode during the Q&A section Alan mentioned that writes to a
ZFS mirror will be at the rate of the slowest disk.  This got me thinking
about the effect of a SLOG as a kind of "front-end" to the mirrored disks.
Which led me this article:
http://www.freenas.org/blog/zfs-zil-and-slog-demystified/

Although it does not mention mirrors, it states that a ZIL exists on every
disk.  So the questions:

1) are ZILs bound to disks, pools, or vdevs?  (ie, where is the 1:1
relationship for ZILs)
2) if ZILs are bound to vdevs and not disks, then is there one ZIL per mirror
and what determines where it lives?
3) if ZILs are bound to disks, then does a SLOG "hide" mulitple ZILs for the
pool with the SLOG attached, bringing the write speed up to the speed of the
SLOG device (or the slowest of a mirrored pair of SLOGs)?  A bit like a
caching reverse proxy (for writes).

Thanks for a great show that I'm sure my dog enjoys too as we walk the park,
Scott
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