Extreme NFS Gateway slow-down when multiple Gateway volumes are present.

Extreme NFS Gateway slow-down when multiple Gateway volumes are present.
When 1 to 3 NFS Gateway volumes are set up, a directory list of 5000 entries takes 25 to 35 seconds.
When 4 or more NFS Gateway volumes are set up, a directory list of 5000 entries takes 14 to 16 minutes.
Smaller directories will also be slower, but to lesser degrees.

After investigating the cause and making several attempts to improve the performance, the developers have concluded that a workable fix would likely require extensive redesign of the NFS 3.0 product as well as possible changes in NSS on NetWare 5.1. It has been concluded that this work cannot be done. There are 3 options for avoiding this issue:

1. Boost the NSS Closed File Cache. This can be done by setting NSS /ClosedFileCacheSize=n. The default on NetWare 5.1 is 512, which is very low. A setting of 50000 is a good place to start. Each cache entry, on average, takes 0.4 to 1 KByte, so a cache of 50000 could take up to 20 to 50 MB RAM. This can be boosted higher (up to a million) if desired and if enough RAM is available. One million entries can take 400 MB to 1 Gigabyte RAM. Boosting the cache size will at least decrease the chances and frequency of this problem. Having it large enough to hold all file and directory entries on the NFS Gateway volumes would completely prevent the problem.

2. Configure only 2 or 3 NFS Gateway volumes on any given NetWare server. For example, depending on the sources and directory structures of the hosts which are exporting the file systems, it may be possible to mount one import containing several sub directories instead of importing those sub directories as separate volumes. Or some volumes can be imported onto one NW 5.1 server, and other volumes can be imported to another NW 5.1 server (assuming there are enough licenses to support additional NFS installations).

3. Upgrade to NFS Gateway for NetWare 6.5 which does not have this problem. (NFS Gateway for NetWare 6.0 also does not have this problem, but that version is no longer available).

Formerly known as TID# 10073993