Halfface - Recent changes [en-gb]

Commands

Ekaanbj — Mon, 25 May 2026 06:03:43 GMT

swapon/swapof

← Older revision		Revision as of 06:03, 25 May 2026
Line 3,103:		Line 3,103:

	=swapon/swapof=		=swapon/swapof=
			View swap usage
			swapon --show
	Free swap		Free swap
	(swapoff -a; swapon -a) & watch free -m		(swapoff -a; swapon -a) & watch free -m

Icinga2

Ekaanbj — Fri, 22 May 2026 13:28:37 GMT

setup oom check

← Older revision		Revision as of 13:28, 22 May 2026
(One intermediate revision by the same user not shown)
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	Why does icinga2 use lots of memory. Look at config and sort by resources		Why does icinga2 use lots of memory. Look at config and sort by resources
	icinga2 daemon -C \| grep information/ConfigItem: \| sort -k6 -n \| tail -5		icinga2 daemon -C \| grep information/ConfigItem: \| sort -k6 -n \| tail -5
			==setup oom check==
			echo "Very critical problem. abjorklund tested to put oom-killer in /var/log/kern.log." >> /var/log/kern.log
			/usr/lib/nagios/plugins/check_log -F /var/log/kern.log -O /tmp/oom_check -q "oom-killer"
			(1) < Very critical problem. abjorklund tested to put oom-killer in /var/log/kern.log.
			/usr/lib/nagios/plugins/check_log -F /var/log/kern.log -O /tmp/oom_check -q "oom-killer"
			Log check ok - 0 pattern matches found
			==nagios client config==
			/etc/nagios/nrpe.cfg
			/etc/nagios/nrpe.d/binero.cfg

Oom

Ekaanbj — Fri, 22 May 2026 13:03:37 GMT

overcommit

← Older revision		Revision as of 13:03, 22 May 2026
Line 27:		Line 27:
	=overcommit=		=overcommit=
	http://engineering.pivotal.io/post/virtual_memory_settings_in_linux_-_the_problem_with_overcommit/		http://engineering.pivotal.io/post/virtual_memory_settings_in_linux_-_the_problem_with_overcommit/
			=search=
			journalctl --grep="oom-killer: "

Openshift

Ekaanbj — Thu, 21 May 2026 08:50:36 GMT

upgrade odf

← Older revision		Revision as of 08:50, 21 May 2026
Line 788:		Line 788:
	# Approve install plan.		# Approve install plan.
	oc get installplans.operators.coreos.com -A --no-headers \| awk '$5 ~ /false/' \| awk '$4 ~ /Manual/' \| while read NAMESPACE INSTALLPLAN END ; do echo '*' $NAMESPACE $INSTALLPLAN ; oc patch installplan $INSTALLPLAN -n $NAMESPACE --type merge --patch '{"spec":{"approved":true}}' ; done		oc get installplans.operators.coreos.com -A --no-headers \| awk '$5 ~ /false/' \| awk '$4 ~ /Manual/' \| while read NAMESPACE INSTALLPLAN END ; do echo '*' $NAMESPACE $INSTALLPLAN ; oc patch installplan $INSTALLPLAN -n $NAMESPACE --type merge --patch '{"spec":{"approved":true}}' ; done
			alternative
			# odf update
			# View current value.
			oc get subscriptions -n openshift-storage odf-operator -o json \| jq .spec
			# Patch to next
			oc patch subscriptions -n openshift-storage odf-operator --type merge -p '{"spec": {"channel": "<channel>"}}'
			# watch progress.
			oc get csv -n openshift-storage -w

	=odf troubleshooting=		=odf troubleshooting=

Commands

Ekaanbj — Wed, 20 May 2026 12:24:06 GMT

systemctl

← Older revision		Revision as of 12:24, 20 May 2026
(9 intermediate revisions by the same user not shown)
Line 3,133:		Line 3,133:

	=systemctl=		=systemctl=
			==troubleshoot systemd==
			export SYSTEMD_LOG_TARGET=console
			export SYSTEMD_LOG_LEVEL=debug

	==init 3==		==init 3==
	systemctl isolate runlevel3.target		systemctl isolate runlevel3.target
Line 3,148:		Line 3,152:
	==List all units==		==List all units==
	systemctl list-unit-files		systemctl list-unit-files

	==List units with problems==		==List units with problems==
	systemctl list-units --failed		systemctl list-units --failed

	==create service==		==create service==
	cd /etc/systemd/system ; vim $service.service ; systemctl daemon-reload		cd /etc/systemd/system ; vim $service.service ; systemctl daemon-reload
Line 3,168:		Line 3,174:
	[Service]		[Service]
	SupplementaryGroups=33 518		SupplementaryGroups=33 518

	==takes a long time to login==		==takes a long time to login==
	systemctl daemon-reexec		systemctl daemon-reexec
	systemctl restart systemd-logind		systemctl restart systemd-logind

	=strace process started by systemctl=		==strace process started by systemctl==
	strace -f -o /tmp/strace.log -s 2048 -p 1 & systemctl restart httpd.service		strace -f -o /tmp/strace.log -s 2048 -p 1 & systemctl restart httpd.service
	=systemctl show puma=
			==systemctl show puma==
	Show variables of service		Show variables of service
	systemctl show puma		systemctl show puma

	=~~systemd-analyze~~=		==systemctl show==
	~~What takes time at startup.~~		will show all available properties
	~~systemd~~-~~analyze plot > /tmp/~~systemd-~~analyze-plot.svg ; chrome /tmp/~~systemd-~~analyze-plot.svg~~		systemctl show $service

			==restart daemon to apply settings==
			systemctl daemon-reload
			systemctl restart systemd-networkd
			systemctl restart systemd-resolved

	=systemd-resolved=		=systemd-resolved=
	resolvectl status		resolvectl status
Line 3,187:		Line 3,201:
	Look at stats.		Look at stats.
	systemd-resolve --statistics		systemd-resolve --statistics
	==~~restart daemon to apply settings==~~		=systemd-analyze=
	~~systemctl daemon~~-~~reload~~		What takes time at startup.
	~~systemctl restart~~ systemd-~~networkd~~		systemd-analyze plot > /tmp/systemd-analyze-plot.svg ; chrome /tmp/systemd-analyze-plot.svg
	~~systemctl restart~~ systemd-~~resolved~~
	~~=systemctl show=~~
	~~will show all available properties~~
	~~systemctl show $service~~

	=tail=		=tail=

Dos

Ekaanbj — Sat, 16 May 2026 11:18:23 GMT

Created page with "=find attackers= grep -F '/wiki/index.php?days=' /var/log/httpd/halfface.se.access.ssl.log | awk '{print "add blocklist " $1 "/32"}' | sort -n | uniq > /tmp/ips_$(date_file).txt =Remove iptables rule that uses ipset list if it already exists= sudo iptables -D INPUT -m set --match-set blocklist src -j DROP =Remove ipset list= sudo ipset destroy blocklist =ipset create list= sudo ipset create blocklist hash:net hashsize 2097152 maxelem 4000000 -exist =Feed ipset list=..."

New page

=find attackers=
grep -F '/wiki/index.php?days=' /var/log/httpd/halfface.se.access.ssl.log | awk '{print "add blocklist " $1 "/32"}' | sort -n | uniq > /tmp/ips_$(date_file).txt
=Remove iptables rule that uses ipset list if it already exists=
sudo iptables -D INPUT -m set --match-set blocklist src -j DROP
=Remove ipset list=
sudo ipset destroy blocklist
=ipset create list=
sudo ipset create blocklist hash:net hashsize 2097152 maxelem 4000000 -exist
=Feed ipset list=
cat /tmp/ips_2026-05-16_12-36-28.txt | sudo ipset restore -exist
=Use list in iptables=
sudo iptables -I INPUT -m set --match-set blocklist src -j DROP