Re: nvme SSD and poor performance

[Marco Möller <talby@debianlists.mobilxpress.net>]

On 20.08.21 18:22, piorunz wrote:
> On 17/08/2021 15:03, Marco Möller wrote:
> > I have no experience with SSD, but running my Debian Desktop from a USB
> > Memory Stick since years, please allow me to share information which
> > supports the suggestion of Linux-Fan to also investigate if there is
> > extraordinary I/O taking place and maybe could be avoided:
> > In the past I found extreme(!) I/O to be produced by Firefox, when it is
> > writing its cache, and when it is writing its session restore
> > information. These writes to my observation occure all the time, kind of
> > nonstop! I could get it very satisfactorily reduced by applying a tool
> > called "Profile Sync Daemon" (psd) from package "profile-sync-daemon".
> > While it is packaged for Debian, as a starting point to study its
> > documentation I suggest to better look it up in the Arch Linux Wiki.
>
> Firefox setting which determines how often write session data to disk is:
> browser.sessionstore.interval
>
> Default setting is value of 15000 = 15 seconds, not that bad. But still
> I changed that to 10 minutes (value of 600000). If I lose an open tab
> once in a year when Firefox crashes, so be it. To be honest, I haven't
> seen Fx crash in a year, or more.
>
> --
>
> With kindest regards, piorunz.
>
> ⢀⣴⠾⠻⢶⣦⠀
> ⣾⠁⢠⠒⠀⣿⡁ Debian - The universal operating system
> ⢿⡄⠘⠷⠚⠋⠀ https://www.debian.org
> ⠈⠳⣄⠀⠀⠀⠀

browser.sessionstore.interval
Storing the session is not the only data written to the disk. If it 
would only be this data, then indeed setting a higher interval would be 
sufficient. But there is much more going on. Especially the cache seems 
to be a cause for the extreme high I/O of Firefox. That's why I finally 
decided to go for the psd tool, and this tool made it for me. Well, I 
assume it has good reasons that someone programmed psd, probably the 
author also noticed that with Firefox parameters alone it often is not 
enough to get the I/O to the HDD caused by Firefox significantly reduced?

I am curious to see what's producing the high jdb2 traffic on the system 
of Pierre, and if this can be stopped and if this finally can be 
attributed to have been the cause for the trouble.

Unfortunately I did not make good notes on how I searched for what was 
causing the traffic on my system, I only remember to have monitored my 
system with iotop and inotifywait.

---
Always stay in good spirits!
Marco