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ZFS also has "general lackluster performance" in areas like using memory (it requires tons of it). It's inherent in the design of a copy-on-write filesystem.
by cmccabe 13y ago
ZFS also has "general lackluster performance" in areas like using memory (it requires tons of it). It's inherent in the design of a copy-on-write filesystem.
According to Ted Dunangst: "ZFS wants a lot of memory. A lot lot lot of memory. So much memory, the kernel address space has trouble wrapping its arms around ZFS. I haven't studied it extensively, but the hack of pushing some of the cache off into higher memory and accessing it through a small window may even work." See http://www.tedunangst.com/flak/post/ZFS-on-OpenBSD http://www.tedunangst.com/flak/post/ZFS-on-OpenBSD
Different filesystems are good for different things. If you want a filesystem that has subvolumes, copy-on-write snapshots, built-in RAID, transactions, space-efficient packing of small files, batch deduplication, checksums on data and metadata, and so forth, you have to pay a price. Just the same way as running Apache with all the bells and whistles is not going to be as fast as ngnix.
- cbsmith 13y ago> ZFS also has "general lackluster performance" in areas like using memory (it requires tons of it). It's inherent in the design of a copy-on-write filesystem. Those benchmarks aren't about CPU or memory consumption. These days a good filesystem probably should trade memory and CPU for increased performance. Those benchmarks are about throughput/latency. > Just the same way as running Apache with all the bells and whistles is not going to be as fast as ngnix. ...except ZFS generally performs very well as compared to other filesystems. When it first came out it had all kinds of ugly corner cases where it performed poorly, but it seems to do great these days.