Take the 2-minute tour ×  Related to this question about using
an SSD for system and HDD for data, except I would like my
system to do this automatically...  Is it possible to have
several layers of storage and push items automatically between
them, using preferably free, open-source software?  I know of
hugely expensive enterprise-class solutions like the EMC
SAN->EMC Centera automatic archiving, but I was wondering if
this sort of staged storage is possible to do automatically.  It
would be nice to be able to have several layers in this :
Memory->SSD->HDD->slower HDD or tape or some other archive
solution.  Are there any filesystems which can do this
automatically? (ZFS, Btrfs, HAMMER?)  Any Unix-variants are
fine, as I'm interested in how this works and whether it's
likely to be portable to Linux or other flavours (BSD etc).
share|improve this question  8 Answers 8  up vote 10 down vote
accepted  Well, ZFS uses a storage layering called Hybrid
Storage Pool (HSP):    1. Layer: memory   2. Layer: SSD-based