CentOS - Aug 2019 - browsers slowing Centos 7 installation to a crawl

On Tue, 6 Aug 2019, Peter wrote:
> On 6/08/19 3:44 AM, Michael Hennebry wrote:
>> In any case, Centos 7 has not always been this slow.
>> Presumably something has changed.
>
> Websites have gotten more resource-intensive.  You've run "yum
updates" and
> now have a newer version of Firefox and/or Chrome.  Your browsing habits
have
> changed and you browse with more tabs open now.
More bloated browsers are not hard to believe in.
My habits haven't change much, though. 
Mostly I use a browser for things I want
to read and things I want to download.
Maybe that is why I'd been getting along with 2GB.
> I have two suggestions for you:
>
> 1.  Run a lightweight desktop such as XFCE instead of Gnome or KDE.
I'll try it.
> 2.  Run out and buy more RAM.  Max your system out at 4G or 8G or whatever
it
> will take.  You will need it and appreciate it.
Maybe.
I open the case with fear and trepidation.
The first time I opened a PC case,
I zapped my video card installing a disk drive.
Under the impressing that memory was the most ststic-sensitive
thing in a PC, I had a friend install the DDR2 memory I'd bought.
'Twas frightening to watch: like wathing The Cat in the Hat
play with one's grandmother's favorite china.
So far as I could tell, he totally ignored the
possbility that static could do bad things.
It worked and I did not have a heart attack.

Also, what is it with DDR2 prices?
When I bought DDR2,
DDR3 was the norm and I paid hundreds of dollars for DDR2.
Do not remember for how much.
Now I suspect DDR4 is the norm and am seeing 8GB of DDR2 for less than $30.
Huh? DDR3 isn't much more.

I'll need to do some digging to discover whether my box needs DDR2 or
DDR3.DDR3
I doubt it's DDR4.


-- 
Michael   hennebry at web.cs.ndsu.NoDak.edu
"Sorry but your password must contain an uppercase letter, a number,
a haiku, a gang sign, a heiroglyph, and the blood of a virgin."
                                                              --  someeecards

In article <alpine.DEB.2.20.1908051718240.19025 at
mail.cs.ndsu.nodak.edu>,
Michael Hennebry <hennebry at web.cs.ndsu.nodak.edu>
wrote:
> 
> I'll need to do some digging to discover whether my box needs DDR2 or
DDR3.DDR3
> I doubt it's DDR4.
Do:

# dmidecode | less

and look for the entries for the existing RAM you have. It will also tell
you if you have any unpopulated RAM slots ("No module installed").

It won't tell you the maximum size RAM each slot will take. For that, you
would need to look up the specs for the motherboard or system (you can find
the model number in the dmidecode output too).

Or you can go to the website for a memory vendor such as Crucial or
Kingston and enter your model number, and it will tell you what RAM is
compatible and what it costs.

Cheers
Tony
-- 
Tony Mountifield
Work: tony at softins.co.uk - http://www.softins.co.uk
Play: tony at mountifield.org - http://tony.mountifield.org

> -----Original Message-----
> From: Tony Mountifield <tony at softins.co.uk>
> Sent: Tuesday, August 06, 2019 5:44 AM
> To: centos at centos.org
> Subject: Re: [CentOS] browsers slowing Centos 7 installation to a crawl
> 
> In article <alpine.DEB.2.20.1908051718240.19025 at
mail.cs.ndsu.nodak.edu>,
> Michael Hennebry <hennebry at web.cs.ndsu.nodak.edu> wrote:
> >
> > I'll need to do some digging to discover whether my box needs DDR2
or
> DDR3.DDR3
> > I doubt it's DDR4.
> 
> Do:
> 
> # dmidecode | less
> 
> and look for the entries for the existing RAM you have. It will also tell
> you if you have any unpopulated RAM slots ("No module
installed").
> 
<SNIP>

In the mean time you could enable zswap[1] to make the most out of the ram and
swap you do have.
according to [2] either add 'zswap.enabled=1' to the boot line or
'echo 1 > /sys/module/zswap/parameters/enabled'

On an EL6 system with 512M of ram (yes that is correct, .5GB, actually ~.4GB
because some is shared with the intel video) I use up-to-date EL6 firefox
reasonably comfortably at home using zswap, setting max_pool_percent to 40.

I am trying to remember which kernel 7 is running (I tend to use the elrepo LT
kernel on EL6) and if it has zswap or only zram.

before switching to the LT kernel I used zram [3] on the machine as swap space
(pretending to be 90% of ram) instead and it works very fast, but when it runs
out (say on a site with lots of JPGs) and you hit real swap again performance
tanks VERY badly.  EL7 may have zram setup to swap in such a way that you can
'sysctl start zram' and try it out.

Good luck.

[1] https://en.wikipedia.org/wiki/Zswap
[2] https://www.kernel.org/doc/html/latest/vm/zswap.html
[3] https://en.wikipedia.org/wiki/Zram

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I am not a contracting officer. I do not have authority to make or modify the
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