Azure Data Lake Storage NFSv3 Protocol support for nconnect for Redhat

Question

Hi,

I have a ADLS Storage Account configured for HNS and NFSv3 protocol support.

When attempting to mount the ADLS container on a Azure RedHat 9.5 NFS Client instance with the nconnect mount option set it fails with.

$ sudo mount /mntfs/adls01c01 

nconnect option needs NFS client with Azure nconnect support!

Mount failed!

Here is the /etc/fstab entry

xxx.blob.core.windows.net:/xxx/adls-01-c01   /mntfs/adls01c01  aznfs defaults,sec=sys,vers=3,nolock,proto=tcp,nofail,_netdev,nconnect=8    1 0

The share does mount successfully without the nconnect option.

I do note the enable_azure_nconnect kernel parm does not exist

$ [ -e /sys/module/sunrpc/parameters/enable_azure_nconnect ] && echo "Yes" || echo "No"

No

I also note this Redhat instance can mount a Azure Files NFS share with nconnect successfully

/etc/fstab entry

xxx.file.core.windows.net:/xxx/auenfs01-share01               /mntfs/nfs01s01   nfs     vers=4,minorversion=1,sec=sys,nconnect=8        0 3

$ sudo mount /mntfs/nfs01s01 

$ mount | grep nfs01s01

xxx.file.core.windows.net:/xxx/auenfs01-share01 on /mntfs/nfs01s01 type nfs4 (rw,relatime,vers=4.1,rsize=1048576,wsize=1048576,namlen=255,hard,proto=tcp,nconnect=8,timeo=600,retrans=2,sec=sys,clientaddr=xxx,local_lock=none,addr=xxx)

A Azure Ubuntu Linux 24.04 instance can mount both shares successfully with nconnect.

Can Microsoft advise when (if at all) Redhat will be able to use nconnect mount option for ADLS NFS shares. Is the fact I can mount a Azure Files NFS share with nconnect supported or do I need a kernel with enable_azure_nconnect?

Thanks

Answer 1

Hi Malcolm Gibbs,
The nconnect option also requires specific kernel support for Azure Files NFS shares. This support is available for NFSv4.1 shares, allowing multiple TCP connections between the client and the Azure Files service, this can significantly improve performance and reduce the total cost of ownership by using fewer client machines
For the latest updates, it's best to keep an eye on announcements from both RedHat and Microsoft Azure.
Reference Link:
https://learn.microsoft.com/en-us/azure/storage/files/nfs-performance

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Answer 2

Hi Malcolm Gibbs - Thanks for reaching out over Q&A Forum.

The nconnect mount option works only on clients that have Azure nconnect support. Using the nconnect option on an unsupported client will decrease throughput and cause commands to timeout or work incorrectly.

The below link also talks about verifying if your kernel supports that or not so you can check it once.

Reference Links:

https://learn.microsoft.com/en-us/azure/storage/blobs/network-file-system-protocol-support-performance#increase-the-number-of-tcp-connections

https://learn.microsoft.com/en-us/azure/storage/blobs/network-file-system-protocol-support-how-to

Hope that helps!

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