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2018-11-24 17:08:00
Clueless
@penfold to answer your question, yes you can boot off ZFS, I believe.
2018-11-24 17:25:48
Rotonen
it can be the root volume pointed at from grub2
2018-11-24 17:26:01
Rotonen
you cannot peacefully cohabit a bootloader on the devices used for zfs
2018-11-24 17:28:29
Fireduck
I remember a lot discussion back in the day about freebsd booting from zfs
2018-11-24 17:28:39
Fireduck
And long guides about doing it
2018-11-24 17:28:47
Fireduck
Seemed not worth the effort
2018-11-24 17:36:12
Rotonen
a non-issue these days so long as you have somewhere grub can be loaded off of
2018-11-24 17:36:39
Rotonen
usb stick on motherboard internal header is a popular choice for home servers
2018-11-24 17:37:46
Clueless
I love the idea of booting from ZFS for like a classroom or work environment
2018-11-24 17:37:59
Clueless
snapshot everyone's workstations daily kinda thing
2018-11-24 17:38:19
Clueless
but that's more a network boot thing
2018-11-24 17:38:32
Fireduck
I usually stick 32gb USB nub in usb socket
2018-11-24 17:38:50
Clueless
it's really only useful for when you have dozens of workstations to manage
2018-11-24 17:39:08
Clueless
I think
2018-11-24 17:43:06
Clueless
eh, it depends
2018-11-24 17:43:28
Clueless
ZFS nets me like 500MB, which is neat
2018-11-24 18:48:52
Rotonen
@fydel so let's turn this into a 'how to munin' general for now
2018-11-24 18:49:16
Rotonen
so first stage stuff first - is rrdcached a thing on your munin master?
2018-11-24 18:49:36
fydel
yes sure.
2018-11-24 18:49:40
fydel
let me check.
2018-11-24 18:50:27
Rotonen
and, as that says, you need to run it as the munin (or www-data) user, as that's in the loop for producing the output, and such security is good enough for most things
2018-11-24 18:50:41
Rotonen
if you need something better, i'll have to get back to you sober and we'll first draft a contract
2018-11-24 18:51:20
Rotonen
but, here is an example systemd file for running one of those as the munin user on debian ``` $ cat /etc/systemd/system/munin-rrdcached.service [Unit] Description=Munin rrdcached [Service] Restart=always User=munin PermissionsStartOnly=yes ExecStartPre=/usr/bin/install -d -o munin -g munin -m 0755 \ /var/lib/munin/rrdcached-journal /run/munin ExecStart=/usr/bin/rrdcached \ -g -B -b /var/lib/munin/ \ -p /run/munin/munin-rrdcached.pid \ -F -j /var/lib/munin/rrdcached-journal/ \ -m 0660 -l unix:/run/munin/rrdcached.sock \ -w 1800 -z 1800 -f 3600 ExecStartPost=/bin/sleep 1 ; /bin/setfacl -m u:www-data:rw /run/munin/rrdcached.sock [Install] WantedBy=multi-user.target ```
2018-11-24 18:52:42
Rotonen
and then you just munin master config use that socket as the rrdcached socket
2018-11-24 18:53:08
Rotonen
i'll dig other stuff up in the meanwhile so once you've had your munin master update on that one two or more times in a row, ping me back
2018-11-24 18:53:59
fydel
okay. give me a couple of minutes.
2018-11-24 19:04:04
Rotonen
does the journal directory exist and does that user have write permissions to it?
2018-11-24 19:13:20
fydel
seems to work. i am just having trouble with the systemd stuff. maybe we check on that later.
2018-11-24 19:13:31
fydel
root@SB35 /var/lib/munin/rrdcached-journal # sudo -u munin /usr/bin/rrdcached -p /run/munin/rrdcached.pid -B -b /var/lib/munin/ -F -j /var/lib/munin/rrdcached-journal/ -m 0660 -l unix:/run/munin/rrdcached.sock -w 1800 -z 1800 -f 3600 -g
2018-11-24 19:13:39
fydel
no erros in /var/log/munin/munin-update.log
2018-11-24 19:13:48
fydel
no errors on console.
2018-11-24 19:14:27
Rotonen
so, how do you serve those html files munin generates?
2018-11-24 19:14:50
fydel
default via cron.
2018-11-24 19:14:54
Rotonen
no, http-wise
2018-11-24 19:16:09
fydel
no. i don't think so.
2018-11-24 19:16:14
fydel
it is generated all five minutes.
2018-11-24 19:16:24
Rotonen
how exactly does a webrowser reach your munin?
2018-11-24 19:16:35
Rotonen
the cronjob generates both html and the png
2018-11-24 19:16:48
Rotonen
now, to get to the next step, we'll need to make the html generation not static
2018-11-24 19:17:04
fydel
symlink. /var/www/html/munin -> /var/cache/munin/www
2018-11-24 19:17:14
Rotonen
munin provides an oldschool cgi script for exactly that
2018-11-24 19:17:28
Rotonen
do you have a `/usr/lib/munin/cgi/munin-cgi-html` ?
2018-11-24 19:17:51
fydel
root@SB35 /var/www/html # ls /usr/lib/munin/cgi/munin-cgi-html /usr/lib/munin/cgi/munin-cgi-html
2018-11-24 19:18:05
Rotonen
how do you prefer to serve cgi scripts these days?
2018-11-24 19:18:27
Rotonen
cgi scripts are a web thing from before php was a thing
2018-11-24 19:18:28
fydel
i dont know. :cry:
2018-11-24 19:18:30
Rotonen
but not too unsimilar
2018-11-24 19:18:31
Rotonen
kk
2018-11-24 19:18:43
Rotonen
so install `spawn-fcgi`, that's useful for us here
2018-11-24 19:19:08
fydel
done
2018-11-24 19:19:41
Rotonen
and i also have a systemd bit for using that, which can be used for ballparking manual usability ``` $ cat /etc/systemd/system/munin-fcgi-html.service [Unit] Description=Munin FastCGI HTML Documentation=man:spawn-fcgi [Service] Type=forking PIDFile=/run/munin/fcgi-html.pid ExecStart=/usr/bin/spawn-fcgi -s /run/munin/fcgi-html.sock -U www-data -u munin -g munin /var/www/cgi-bin/munin-cgi-html -P /run/munin/fcgi-html.pid [Install] WantedBy=multi-user.target ```
2018-11-24 19:20:06
Rotonen
and that's just a symlink `/var/www/cgi-bin/munin-cgi-html -> /usr/lib/munin/cgi/munin-cgi-html`
2018-11-24 19:20:51
Rotonen
if you want your munin to rely on cgi for generating the html, you need to tell it to use that as the generation strategy
2018-11-24 19:21:00
Rotonen
let's do that first as that's a bit easier than the graphs
2018-11-24 19:21:45
Rotonen
and as i do not know which webfront you use, here are some relevant location snippets for nginx ``` location ^~ /munin-cgi/munin-cgi-graph/ { access_log off; fastcgi_split_path_info ^(/munin-cgi/munin-cgi-graph)(.*); fastcgi_param PATH_INFO $fastcgi_path_info; fastcgi_pass unix:/run/munin/fcgi-graph.sock; include fastcgi_params; } location /munin/static/ { alias /etc/munin/static/; } location /munin/ { fastcgi_split_path_info ^(/munin)(.*); fastcgi_param PATH_INFO $fastcgi_path_info; fastcgi_pass unix:/run/munin/fcgi-html.sock; include fastcgi_params; } ```
2018-11-24 19:21:51
Rotonen
and you should cache those on disk for 5 minutes
2018-11-24 19:22:39
Rotonen
and here's a systemd example for wrapping the graphs ``` $ cat /etc/systemd/system/munin-fcgi-graph.service [Unit] Description=Munin FastCGI Graph Documentation=man:spawn-fcgi [Service] Type=forking PIDFile=/run/munin/fcgi-graph.pid ExecStart=/usr/bin/spawn-fcgi -s /run/munin/fcgi-graph.sock -U www-data -u munin -g munin /var/www/cgi-bin/munin-cgi-graph -P /run/munin/fcgi-graph.pid [Install] WantedBy=multi-user.target ```
2018-11-24 19:22:58
Rotonen
and if you get that going for you, the interactive graphs will work
2018-11-24 19:24:43
Rotonen
so there you have all the facts assembled, i can help with specifics if you hit something
2018-11-24 19:28:50
fydel
i am on it.
2018-11-24 19:28:53
Rotonen
and of course only cache the html outputs, the graph ones need to be direct accesses to the cgi script
2018-11-24 19:29:04
Rotonen
i'll be on the computer all evening, you're not in a rush
2018-11-24 19:30:20
fydel
i am using apache2. same for apache instead of nginx?
2018-11-24 19:30:48
Rotonen
well, yes, but you need to figure out those redirects of how to talk to the unix domain sockets of the fcgi wrapped scripts
2018-11-24 19:31:10
Rotonen
fcgi wrappers can also usually provide you a tcp interface if that makes life easier to you
2018-11-24 19:40:48
fydel
oh, man. that's too much for me.
2018-11-24 19:41:29
fydel
i am not into webserver and this cgi stuff.
2018-11-24 19:41:52
fydel
and i never used systemd before.
2018-11-24 19:45:53
fydel
i have to read up about this stuff before we can continue.
2018-11-24 19:47:47
Rotonen
well, you have it archived here now
2018-11-24 19:48:03
Rotonen
but munin is just a pile of perl and cgi on top of rrd and rrdcached
2018-11-24 19:48:18
Rotonen
did your munin master runs get faster at least?
2018-11-24 19:49:27
fydel
yes. thanks so far.
2018-11-24 19:50:18
fydel
no. :disappointed: