> As I've said here on the list a few times earlier, the last on the > thread 'ZFS not usable (was ZFS Dedup question)', I've been doing some > rather thorough testing on zfs dedup, and as you can see from the > posts, it wasn't very satisfactory. The docs claim 1-2GB memory usage > per terabyte stored, ARC or L2ARC, but as you can read from the post, > I don't find this very likely.
Sorry about the initial post - it was wrong. The hardware configuration was right, but for initial tests, I use NFS, meaning sync writes. This obviously stresses the ARC/L2ARC more than async writes, but the result remains the same. With 140GB with of L2ARC on two X25-Ms and some 4GB partitions on the same devices, 4GB each, in a mirror, the write speed was reduced to something like 20% of the origian speed. This was with about 2TB used on the zpool with a single data stream, no parallelism whatsoever. Still with 8GB ARC and 140GB of L2ARC on two SSDs, this speed is fairly low. I could not see substantially high CPU or I/O load during this test. Vennlige hilsener / Best regards roy -- Roy Sigurd Karlsbakk (+47) 97542685 r...@karlsbakk.net http://blogg.karlsbakk.net/ -- I all pedagogikk er det essensielt at pensum presenteres intelligibelt. Det er et elementært imperativ for alle pedagoger å unngå eksessiv anvendelse av idiomer med fremmed opprinnelse. I de fleste tilfeller eksisterer adekvate og relevante synonymer på norsk. _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
