/var/spool/imap on ZFS

[Andre Felipe Machado]

Hello, 

Some suggestions for general guidance: 

- Avoid deduplication. Maybe use compression at low level or fast algorithm to get dedup effect ALSO. With compression you get dynamic sector size also. 

- RAIDZn is for space, not for performance. Beware. 

- RAIDZn is not cheap to expand. 

- Place your indexes/metadata at different zpool of disks/ssd configured for absolute max performance. Indexes and metadata are "small" compared to data. Up to 20%. 

- RAM, more RAM, much more RAM. Did you get RAM? Is not enough. Buy more RAM. 

- Buy the fastest SLOG device you could. ZeusRAM is one of the suggestions. 

- Cyrus most writes are simultaneus variable size small random synchronous. THE nightmare for all filesystems and storage. Keep in mind. 

- maybe this article could help with some info: http://www.techforce.com.br/content/zfs-part-4-multithreaded-sustained-random-small-files-synchronous-write-iops 

  

Good luck. 

Andre Felipe 

  

Mikhail T. <mi+cyrus at aldan.algebra.com> wrote ..  

I'd like to move my current spool from a single (fast) disk to ZFS. Any suggestions for the filesystem-parameters? 

Do I want deduplication, for example? Compression? Recordsize? 

Thanks!  

-mi   

  
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