RE:

We've seen a lot of problems with the newer behavior failing to react quick enough. It CAN jump up to 64K slot table entries, but it doesn't seem to happen quick enough. We usually recommending pinning all the slot table settings to 128 and leaving them there. That ensures that it's ready for the bursts of IO.

I'm sure someone out there needs > 128, but we haven't clearly identified such a workload yet.

From: Toasters <[email protected]> On Behalf Of Fenn, Michael
Sent: Tuesday, July 7, 2020 9:29 AM
To: Scott Eno <[email protected]>; tmac <[email protected]>; Parisi, Justin <[email protected]>
Cc: Toasters <[email protected]>
Subject: Re:

NetApp Security WARNING: This is an external email. Do not click links or open attachments unless you recognize the sender and know the content is safe.


On more recent kernels, these are now sysctl parameters.  You can put the following in /etc/sysctl.conf (or a new .conf file in /etc/sysctl.d) and run sysctl -w (or reboot):

sunrpc.tcp_max_slot_table_entries = 128
sunrpc.tcp_slot_table_entries = 128
sunrpc.udp_slot_table_entries = 64

That being said, you might want to check your current settings.  At least on CentOS 7, sunrpc.tcp_max_slot_table_entries defaults to 65536, which is greater than the NetApp tuning, and should be more than large enough to ensure good write performance.

Side note, hard has been the default for a while now, and intr has been ignored for over a decade, so you can skip those (though they're not harmful to provide).

Thanks,
Michael

From: Scott Eno <[email protected]<mailto:[email protected]>>
Date: Tuesday, July 7, 2020 at 8:46 AM
To: tmac <[email protected]<mailto:[email protected]>>, "Parisi, Justin" <[email protected]<mailto:[email protected]>>
Cc: Toasters <[email protected]<mailto:[email protected]>>
Subject: Re: Re:

NetApp docs talk about these settings:
udp_slot_table_entries=64
tcp_slot_table_entries=128
tcp_max_slot_table_entries=128

as being for RHEL 6.3 and above.  The system I'm helping a user with is Ubuntu 18.04.3.  Do these settings still apply (noting there's currently no sunrpc.co, or sunrpc.conf, under modprobe.d).
"Parisi, Justin" <[email protected]<mailto:[email protected]>> wrote:
Just an FYI a new update to that TR is coming soon.



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________________________________
From: Toasters <[email protected]<mailto:[email protected]>> on behalf of tmac <[email protected]<mailto:[email protected]>>
Sent: Monday, July 6, 2020 9:51:07 PM
To: Scott Eno <[email protected]<mailto:[email protected]>>
Cc: Toasters <[email protected]<mailto:[email protected]>>
Subject: Re:

NetApp Security WARNING: This is an external email. Do not click links or open attachments unless you recognize the sender and know the content is safe.




https://www.netapp.com/us/media/tr-4067.pdf


Hard, intr, nfsvers=3, rsize=65536,wsize=65536,proto=tcp,mountproto=tcp


Dont forget to modify the client to increase/set tcp_max_slot_table_entries to 128.


--tmac


Tim McCarthy, Principal Consultant
Proud Member of the #NetAppATeam<https://twitter.com/NetAppATeam>
I Blog at TMACsRack<https://tmacsrack.wordpress.com/>





On Mon, Jul 6, 2020 at 8:45 PM Scott Eno via Toasters <[email protected]<mailto:[email protected]>> wrote:



---------- Forwarded message ----------
From: Scott Eno <[email protected]<mailto:[email protected]>>
To: Toasters <[email protected]<mailto:[email protected]>>
Cc:
Bcc:
Date: Tue, 07 Jul 2020 00:42:56 +0000
Subject: fstab nfsv3 mount favorites?
Hi,

It’s been a number of years since I worked in a Linux/NFS shop, so while I search for my old fstab mount options for a one-off project, does anyone have their go-to fstab nfsv3 mount options handy?  The exported volume is on an ONTAP 9.6 cluster if it matters.



---------- Forwarded message ----------
From: Scott Eno via Toasters <[email protected]<mailto:[email protected]>>
To: Toasters <[email protected]<mailto:[email protected]>>
Cc:
Bcc:
Date: Tue, 7 Jul 2020 01:43:01 +0100
Subject:
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