Merge pull request #209248 from ekpgh/hpc-misc-items

Add troubleshooting tip about insufficient threads

Author: prmerger-automator[bot]

articles/hpc-cache/troubleshoot-nas.md

@@ -4,7 +4,7 @@ description: Tips to avoid and fix configuration errors and other problems that
 author: ekpgh    
 ms.service: hpc-cache
 ms.topic: troubleshooting
-ms.date: 05/27/2022
+ms.date: 08/29/2022
 ms.author: v-erinkelly
 ---
 
@@ -19,6 +19,12 @@ This article includes details about how to check ports and how to enable needed
 
 If the solution to your problem is not included here, please [open a support ticket](hpc-cache-support-ticket.md) so that Microsoft Service and Support can work with you to investigate and solve the problem.
 
+## Provide sufficient connection threads
+
+Large HPC Cache systems make multiple connection requests to a storage target. For example, if your storage target uses the Ubuntu Linux `nfs-kernel-server` module, the default number of NFS daemon threads can be as low as eight. Increase the number of threads to 128 or 256, which are more reasonable numbers to support a medium or large HPC Cache.
+
+You can check or set the number of threads in Ubuntu by using the RPCNFSDCOUNT value in `/etc/init.d/nfs-kernel-server`.
+
 ## Check port settings
 
 Azure HPC Cache needs read/write access to several UDP/TCP ports on the back-end NAS storage system. Make sure these ports are accessible on the NAS system and also that traffic is permitted to these ports through any firewalls between the storage system and the cache subnet. You might need to work with firewall and network administrators for your data center to verify this configuration.