Arch Linux

ptunstall

Member

Registered: 2021-06-21

Posts: 4

NFS Server: Increase max connection limit?

I seem to be hitting some max NFS connection limit when I reach about 40 connections/clients.  I get connection denied after this.

I went through this: https://wiki.archlinux.org/title/NFS/Troubleshooting

and this: https://wiki.archlinux.org/title/NFS

And I can't seem get around this issue.  Has anyone built an Archlinux NFS server that works with 100+ NFS clients?

I'm sorry if this has been asked, I tried using the search feature but it resulted in an error message every time.

Thanks,
Patton

seth

Member

From: Won't reply 2 private help req

Registered: 2012-09-03

Posts: 77,438

Re: NFS Server: Increase max connection limit?

http://people.redhat.com/jmoyer/nfs-limits.html
https://utcc.utoronto.ca/~cks/space/blo … ntTunables

% sysctl -a | grep -i sunrpc
sunrpc.max_resvport = 1023
sunrpc.min_resvport = 665
sunrpc.nfs_debug = 0x0000
sunrpc.nfsd_debug = 0x0000
sunrpc.nlm_debug = 0x0000
sunrpc.rpc_debug = 0x0000
sunrpc.tcp_fin_timeout = 15
sunrpc.tcp_max_slot_table_entries = 65536
sunrpc.tcp_slot_table_entries = 2
sunrpc.transports = tcp 1048576
sunrpc.transports = udp 32768
sunrpc.udp_slot_table_entries = 16

Though I think tcp_slot_table_entries is dynamic and probably not critical (a sentence tha is no going to haunt me ;-)
udp_slot_table_entries might be if you run NFS on UDP.
"sunrpc.min_resvport = 1" might get you ahead.

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ptunstall

Member

Registered: 2021-06-21

Posts: 4

Re: NFS Server: Increase max connection limit?

Wonderful! I'll test this first thing in the AM and report back.  Much appreciated in advance!!

ptunstall

Member

Registered: 2021-06-21

Posts: 4

Re: NFS Server: Increase max connection limit?

Still working on this, definitely is something to do with these settings and some complementary client side setting just trying to figure out the right workflow.  Found this: https://www.suse.com/support/kb/doc/?id=000017508.  Seeing as this appears to not be an "Archlinux" thing I'll leave this alone until I found a solution.  Big time appreciate the sunrpc hint!!

ptunstall

Member

Registered: 2021-06-21

Posts: 4

Re: NFS Server: Increase max connection limit?

Making some progress in Debian tweaking the settings you shared and adjusting the exports/fstab settings, will test this weekend with Arch.  Connected 52 without issue.  I'll share all my findings if this works!

Few notes:

adding "insecure" on exports allows for binding outside the protected port range.
It helps if I get the right netmask correct, /24 works for 256, but I needed /20 --