topic CIFS connection limits in Network and Storage Protocols

CIFS connection limits

Gundersen89 — Wed, 04 Jun 2025 12:54:17 GMT

Hi all

In my company we have got quite a big old traditional NAS solutions (around 1PB in each of the 2 sites). We have around +30.000 users who has their own home share and multiple shared CIFS shares. We know that the number of client connections are quite high (around 30.000 at a time during working hours) and that it may affect performance.

Im not familiar with Netapp products but can anyone tell me how big numbers of CIFS connections from clients, the netapp products can handle up to?
I know that some other vendors has limits around 20.000 Connections pr cluster, which is a problem with our architechture at the moment.

Best Regards

Sebastian

Re: CIFS connection limits

SpindleNinja — Thu, 31 Jan 2019 20:47:37 GMT

Just looking a few examples for you:

FAS8200/ A300/A700 running ONTAP 9.5 Maximum number of open files is 1,500,000.

FAS2650/2750/A200/A220 - Maximum number of open files is 600,000

(all values per HA pair)

Keep in mind there is a lot more to sizing and configuing a system then just the open file metric. I do a lot of these for customers, let me know if you have any questions.
All this can be found on the HW - https://hwu.netapp.com

Re: CIFS connection limits

Gundersen89 — Fri, 01 Feb 2019 09:17:12 GMT

Thanks for your fast reply @SpindleNinja
I don't believe that "Maximum number of open files is 1,500,000" is the same as SMB connections to a node or a cluster. Have you got any numbers for this?

I think we are going to invite Netapp for a cup of coffee and tell us what they can do, but I wouldn't waste time on this, if they had some known limits that I allready knew would conflict with our invironment.

Best regards

Sebastian

Re: CIFS connection limits

GidonMarcus — Fri, 01 Feb 2019 10:11:58 GMT

Ask you partner or NetApp contact to look for the following two limits in their tools/Docs

Core - Maximum number of connections - NAS

CIFS - Maximum number of connected share

I took notes of these for my platform when A NetApp engineer helped me to size my system (it was FAS3250 HA with ONTAP 9.0, the first figure was 100K Per HA (no cluster limit), and the second was 500K per HA (no cluster limit).

So this fairly old small spec controller (20GB RAM) and old OS version could do more than what sounds like you need.

Gidi

Re: CIFS connection limits

SpindleNinja — Fri, 01 Feb 2019 14:10:17 GMT

I read it as per ha pair, but yep. sit down with your local netapp rep / partner and have a chat with them.

Re: CIFS connection limits

GLENYU5820 — Sun, 03 Feb 2019 19:57:12 GMT

The max-mpx is the option you are talking about. The default is 255. You can modify it via cifs options modify command.