Date: Wed, 17 Mar 2021 02:31:30 +0000 From: Rick Macklem <rmacklem@uoguelph.ca> To: Alan Somers <asomers@freebsd.org> Cc: freebsd-fs <freebsd-fs@freebsd.org> Subject: Re: Understanding the vfs.nfsd.request_space* sysctls Message-ID: <YQXPR0101MB096871CFED5ADA41FC22713FDD6A9@YQXPR0101MB0968.CANPRD01.PROD.OUTLOOK.COM> In-Reply-To: <CAOtMX2ih9cLq3-Mw9xw3T9ovBiZ%2BY3PG82pN0s2eVusRooRF_g@mail.gmail.com> References: <CAOtMX2geF7Tv7VYc9WtK23a%2BnDzJzD2ehVKp94=xANjTA9S9Tg@mail.gmail.com> <YQXPR0101MB0968CD521F2A19F44488367ADD6B9@YQXPR0101MB0968.CANPRD01.PROD.OUTLOOK.COM>, <CAOtMX2ih9cLq3-Mw9xw3T9ovBiZ%2BY3PG82pN0s2eVusRooRF_g@mail.gmail.com>
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Alan Somers wrote: [stuff snipped] >That all makes sense. So having a high request_space_used basically just means that >my storage is too slow. Since it appears that you have plenty of nfsd threads, that would imply that the bottleneck is probably the file system. (You might want to check that there is cpu available. ie. Some amount of idle cpu, just in case?) [more stuff snipped] >I've added an L2ARC since I sent that original email. We'll see how well it works. I >expect it to take 48 hours before results are apparent. Others have tweaked something so that more of the arc is used for metadata. [more stuff snipped] >Experimentally, I determined that 768 threads is sufficient. But your formula would >suggest > 2500, which is a lot of threads! I'll keep it in mind if I ever reach 768, >though. 768 is probably plenty. My number would be an extreme upper bound. I did it because the default of 8 per cpu is very low (assumes a machine mostly doing other things). Good luck with it, rick rick -Alan _______________________________________________ freebsd-fs@freebsd.org<mailto:freebsd-fs@freebsd.org> mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-fs To unsubscribe, send any mail to "freebsd-fs-unsubscribe@freebsd.org<mailto:freebsd-fs-unsubscribe@freebsd.org>"home | help
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