Hi, Erik, I've always wondered what the benefit (and difficulty to add to ZFS) would > be to having an async write cache for ZFS - that is, ZFS currently buffers > async writes in RAM, until it decides to aggregate enough of them to flush > to disk. I think it would be interesting to see what would happen if an > async SSD cache was available, since the write pattern is "large, > streaming", which means that the same devices useful for L2ARC would perform > well as an async write cache. In essence, use the async write SSD as an > extra-large buffer, in the same way that L2ARC on SSD supplements main > memory for the read cache. > > I think HDD can handle those "large and streaming like" workload quite well. You can observe SSD doesn't play very much better than HDD on streaming write/read. So it could be good enough to flush those async aggreated write data back to HDD instead of bringing another level of write cache.
> -- > Erik Trimble > Java System Support > Mailstop: usca22-123 > Phone: x17195 > Santa Clara, CA > > > _______________________________________________ > zfs-discuss mailing list > zfs-discuss@opensolaris.org > http://mail.opensolaris.org/mailman/listinfo/zfs-discuss >
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