Nataraj wrote:

On 03/01/2012 08:15 AM, m.roth@5-cent.us wrote:

...

We just moved a user, who deals with a *lot* of data, to a new server,

since his old NFS home directory was on a disk that had started showing problems.

...

Now, i/o is about six times slower, my manager reports.

<snip> Ok, more info: at this point, it seems obvious that it's an NFSv4 problem, not a network problem: I've created /scratch/foo, exported it, and mounted it on the same machine at /mnt/foo. I then cd to that directory, and unpack a large file which is located in a user's home directory which is NFSv4 mounted. In a native directory, takes about a minute; when I cd to /mnt/foo and do it, it takes about 6.5 min. I've tried setting wsize and rsize to 1M; I've tried noatime, which someone in a post said helped, and nothing I do makes more than a second or two's difference.

Clues for the poor?

mark