Re: emacs find-file extremely slow over sshfs+vpn

[Kim Barrett]

> On Sep 4, 2023, at 6:20 AM, Michael Albinus <michael.albinus@gmx.de> wrote:
> 
> Kim Barrett <kab@conundrums.ca> writes:
> 
> Hi Kim,
> 
>> I'm trying to use emacs (29.1-1, also 28.2 and 28.1-4) on MacOS to edit files
>> on a remote machine via VPN and sshfs. (Mac-compatible emacs obtained from
>> https://emacsformacosx.com/builds.) Using emacs to read or write such files
>> takes a very long time, like 2-3 minutes. These are not large files. 
>> Obviously
>> this very usable.
>> 
>> It seems like the VPN is connected to the problem, since I don't see such a
>> delay when reading and writing files accessed via sshfs on a remote machine
>> that doesn't need VPN for access.
>> 
>> The network performance over VPN isn't amazing, but by itself it's nowhere
>> near bad enough to account for what I'm seeing with emacs. And I don't see
>> anything like that slowdown with other applications (including Aquamacs, a 
>> mac
>> port of emacs 25).
>> 
>> Searching the web finds various similar sounding complaints of various
>> vintages, but I'm not finding anything that matches what I'm seeing and has a
>> solution.
>> 
>> Any suggestions? I'd really like to switch to a recent version of emacs (I've
>> been using Aquamacs, but it's been stuck on emacs 25 for a long time). But
>> this problem makes that impossible for one of my main uses.
> 
> In my experience, it matters to set proper cache values for sshfs. Read
> the man page.

Playing with caching options seems to me unlikely to fix my problem, since I
only see it with emacs, not with anything else (including Aquamacs, a MacOS
port of emacs 25). Emacs seems to be doing "something" when used over my
sshfs+vpn configuration, but I've no idea what or how to find out.

I spent some time fiddling with cache options anyway, and didn't detect any
improvements.

> Alternatively, you could try Tramp for accessing your remote files via
> its "ssh" method. Read the Tramp manual.
> 
> Best regards, Michael.