Plans for 1.8+ (2.0?)

Bill Hacker wbh at
Thu Feb 1 04:48:38 PST 2007

Tobias Schacht wrote:
On 2/1/07, Matthew Dillon <dillon at> wrote:

    No, its a lot more complex then that.  There are three basic issues:

    * Redundancy in a heavily distributed environment

    * Transactional Consistency.

    * Cache Coherency and conflict management.
Hm, I wonder how plan9 solved these issues? AFAIK they have at least a
snapshots capable fs (long before zfs) and since their scope also is a
distributed environment, it may be a good idea to take a look and
maybe borrow some ideas?
But I'm really no expert here, so anybody with a clue is invited to
comment on that. ;)
The Plan 9 storage (two distinct types) was 'widely sharable', not clustered, 
per se.

One might make the case that it had more in common with NFS than clustering.

BUT.. it had a mechanism to insure 'current status' more familiar to table, row, 
record locking schemes of an RDBMS (which ZFS has a kinship with).

Simple hash-based, these were an order or two of magnitude simpler - hence 
faster - than  ZFS could be on the same hardware.

The consatnt 'snapshot-ing' OTOH, could have placed major strains on the paltry 
storage of the day (for anyone with less funding than AT&T anyway).

That last part has changed.

With capacity and cost of current HDD, it is probably now faster and cheaper to 
'abandon in place' a good deal of stale data than to even bother to go back and 
look at it at all - let alone clean it up, make decisions as to what to archive, 

Not complex, and certainy worth a look for recyclable ideas. her is an analysis 
of 'in-use' history:


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