> -----Original Message-----
> From: neil.per...@sun.com [mailto:neil.per...@sun.com]


> I think you misunderstand the function of the ZIL. It's not a journal,
> and doesn't get transferred to the pool as of a txg. It's only ever
> written except
> after a crash it's read to do replay. See:
> 
> http://blogs.sun.com/perrin/entry/the_lumberjack

I also read another blog[1]; the part of interest here is this:

The zil behaves differently for different size of writes that happens. For 
small writes, the data is stored as a part of the log record. For writes 
greater than zfs_immediate_write_sz (64KB), the ZIL does not store a copy of 
the write, but rather syncs the write to disk and only a pointer to the sync-ed 
data is stored in the log record.

If I understand this right, writes <64KB get stored on the SSD devices. 

[1] http://blogs.sun.com/realneel/entry/the_zfs_intent_log
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