[OpenIndiana-discuss] Fwd: poor zfs compression ratio

[Roy Sigurd Karlsbakk]

> We are trying to backup our emails by copying (via rsync) them to a
> different storage server where we have recently installed
> openindiana[1] so
> we can take advantage of inbuilt compression and deduplication
> features of
> zfs but to our surprise, the compression ratio seem to be pretty low.

Please keep in mind that dedup in zfs isn't ready for production. If you still choose to use it, you'll need massive amounts of memory+L2ARC, typically 2GB RAM per 1TB stored data if the majority uses 128kB records. With email, the majority of the data blocks are likely to be far smaller, meaning a larger DDT, and more memory requirements. I've done rather a lot of testing of zfs dedup, and others have done even more and better structured testing, and found it not useful for production. Search the archives...

Vennlige hilsener / Best regards

roy
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Roy Sigurd Karlsbakk
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roy at karlsbakk.net
http://blogg.karlsbakk.net/
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