On 01/17/2012 09:15 PM, Chuck Lever wrote:

Hi-

I know there is some work on ext4 regarding metadata corruption
detection; btrfs also has some corruption detection facilities.  The
IETF NFS working group is considering the addition of corruption
detection to the next NFSv4 minor version.  T10 has introduced
DIF/DIX.

I'm probably ignorant of the current state of implementation in
Linux, but I'm interested in understanding common ground among local
file systems, block storage, and network file systems.  Example
questions include:  Do we need standardized APIs for block device
corruption detection?  How much of T10 DIF/DIX should NFS support?
What are the drivers for this feature (broad use cases)?

Other network file systems such as Lustre already use their own network 
data checksums. As far as I know Lustre plans (planned?) to use 
underlying ZFS checksums also for network transfers, so real 
client-to-disk (end-to-end) checksums. Using T10 DIF/DIX might be on 
their todo list.

We from the Fraunhofer FhGFS team would like to also see the T10 DIF/DIX 
API exposed to user space, so that we could make use of it for our FhGFS 
file system.
And I think this feature is not only useful for file systems, but in 
general, scientific applications, databases, etc also would benefit from 
insurance of data integrity.


Cheers,
Bernd


--
Bernd Schubert
Fraunhofer ITWM