Re: ACID Question

[Andi Kleen <ak@xxxxxx>]

Rick Spillane <necro351@xxxxxxxxx> writes:

> Does XFS entirely follow the ACID requirements: Atomic, Consistancy,
> Isolated, and Durability?

For user data (read/write) etc. no. It follows POSIX semantics for that, 
which are much weaker.  You can implemented full ACID on top of 
it though using fsync/fdatasync/O_SYNC. 

It probably does for internal transactions on its disk data structures
(like updating directories or inodes), but user visible actions
(rename, create file etc.) are also not necessary atomic or isolated
because the Linux VFS often splits them up into multiple actions.
They should be all consitent in itself though and durable if you
flush the data at some point (fsync).

-Andi