NFS - slow

[Wojciech Puchar]

> the server is required to do that. (ie. Make sure the data is stored on
> stable storage, so it can't be lost if the server crashes/reboots.)
> Expensive NFS servers can use non-volatile RAM to speed this up, but a generic
> FreeBSD box can't do that.
>
> Some clients (I believe ESXi is one of these) requests FILE_SYNC all the
> time, but all clients will do so sooner or later.
>
> If you are exporting ZFS volumes and don't mind violating the NFS RFCs
> and risking data loss, there is a ZFS option that helps. I don't use
> ZFS, but I think the option is (sync=disabled) or something like that.
> (ZFS folks can help out, if you want that.) Even using vfs.nfsrv.async=1
> breaks the above.


thank you for answering. i don't use or plan to use ZFS. and i am aware of 
this NFS "feature" but i don't understand - even with syncs disabled, why 
writes are not clustered. i always see 32kB writes in systat


when running unfsd from ports it doesn't have that problem and works 
FASTER than kernel nfs.