On 12/02/18 17:06, J. Bruce Fields wrote:
On Mon, Feb 12, 2018 at 09:08:47AM +0000, Terry Barnaby wrote:
On 09/02/18 08:25, nicolas.mailhot@xxxxxxxxxxx wrote:
----- Mail original -----
De: "Terry Barnaby"
If
it was important to get the data to disk it would have been using
fsync(), FS sync, or some other transaction based app
??? Many people use NFS NAS because doing RAID+Backup on every client is too expensive. So yes, they *are* using NFS because it is important to get the data to disk.
Regards,
Yes, that is why I said some people would be using "FS sync". These people
would use the sync option, but then they would use "sync" mount option,
(ideally this would be set on the NFS client as the clients know they need
this).
The "sync" mount option should not be necessary for data safety.
Carefully written apps know how to use fsync() and related calls at
points where they need data to be durable.
The server-side "async" export option, on the other hand, undermines
exactly those calls and therefore can result in lost or corrupted data
on a server crash, no matter how careful the application.
Again, we need to be very careful to distinguish between the client-side
"sync" mount option and the server-side "sync" export option.
--b.
One thing on this, that I forgot to ask, doesn't fsync() work properly
with an NFS server side async mount then ? I would have thought this
would still work correctly.
_______________________________________________
devel mailing list -- devel@xxxxxxxxxxxxxxxxxxxxxxx
To unsubscribe send an email to devel-leave@xxxxxxxxxxxxxxxxxxxxxxx
