From: Alkis Georgopoulos <alkisg@gmail.com>
To: Trond Myklebust <trondmy@hammerspace.com>,
"linux-nfs@vger.kernel.org" <linux-nfs@vger.kernel.org>
Subject: Re: rsize,wsize=1M causes severe lags in 10/100 Mbps
Date: Thu, 19 Sep 2019 23:20:39 +0300 [thread overview]
Message-ID: <5601db40-ee2f-262d-7d01-5c589c9a07eb@gmail.com> (raw)
In-Reply-To: <1d5f6643330afd2c04350006ad2a60e83aebb59d.camel@hammerspace.com>
On 9/19/19 11:05 PM, Trond Myklebust wrote:
> There are plenty of operations that can take longer than 700 ms to
> complete. Synchronous writes to disk are one, but COMMIT (i.e. the NFS
> equivalent of fsync()) can often take much longer even though it has no
> payload.
>
> So the problem is not the size of the WRITE payload. The real problem
> is the timeout.
>
> The bottom line is that if you want to keep timeo=7 as a mount option
> for TCP, then you are on your own.
>
The problem isn't timeo at all.
If I understand it correctly, when I try to launch firefox over nfsroot,
NFS will wait until it fills 1M before "replying" to the application.
Thus the applications will launch a lot slower, as they get "disk
feedback" in larger chunks and not "snappy".
In numbers:
timeo=600,rsize=1M => firefox opens in 30 secs
timeo=600,rsize=32k => firefox opens in 20 secs
Anyway, thank you very much for your time and feedback.
Kind regards,
Alkis Georgopoulos
next prev parent reply other threads:[~2019-09-19 20:20 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-19 7:29 rsize,wsize=1M causes severe lags in 10/100 Mbps, what sets those defaults? Alkis Georgopoulos
2019-09-19 15:08 ` Trond Myklebust
2019-09-19 15:58 ` rsize,wsize=1M causes severe lags in 10/100 Mbps Alkis Georgopoulos
2019-09-19 16:11 ` Trond Myklebust
2019-09-19 19:21 ` Alkis Georgopoulos
2019-09-19 19:51 ` Trond Myklebust
2019-09-19 19:57 ` Alkis Georgopoulos
2019-09-19 20:05 ` Trond Myklebust
2019-09-19 20:20 ` Alkis Georgopoulos [this message]
2019-09-19 20:40 ` Trond Myklebust
2019-09-19 21:19 ` Daniel Forrest
2019-09-19 21:42 ` Trond Myklebust
2019-09-19 22:16 ` Daniel Forrest
2019-09-20 9:25 ` Alkis Georgopoulos
2019-09-20 9:48 ` Alkis Georgopoulos
2019-09-20 10:04 ` Alkis Georgopoulos
2019-09-21 7:52 ` Alkis Georgopoulos
2019-09-21 7:59 ` Alkis Georgopoulos
2019-09-21 11:02 ` Alkis Georgopoulos
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