Purely from interest, is there any current FOSS implementation of HSM?
I note that XFS has dropped support for DMAPI, have other filesystems?
having dealt with various HSM implementations at a API level, where we were using them to secure our own proprietary PKI systems, POX on that whole architecture, its an ungodly mess. I’m not even remotely surprised XFS has ditched anything related to it.
I think there may be some confusion here. By HSM I was referring to Hierarchical Storage Management, whereby there are multiple levels of storage (fast+expensive < -> slow+cheap) and files migrate up or down. Originally it was used to keep data on tape with the metadata residing on disk though it has been expanded to allow a SAS/SATA hierarchy. Quite where PKI comes in I’m not sure, unless you are implementing it over an external network.
HSM also stands for “Hardware security module”
Maybe lvmcache would be interesting for you? HSM is more popularly known as
Hmm, don’t you just love changing terminology! I’ve been using HSM
systems at work since ’99. BTW, DMAPI is the Data Management API which was a common(ish) extension used by amongst others SGI and IBM.
Back to lvmcache. It looks interesting. I’d earlier dismissed LVM
since it is block orientated, not file orientated. Probably because my mental image is of files migrating to tapes in a silo.
ZFS also does some fun things here if you want to build an SSD & spinning disk array – http://zfsonlinux.org/
Interesting – the ARC seems to do just that at first glance. I may have a look at it this evening.