Category / SysAdmin

After reading cron.weekly a few weeks ago, I was intrigued by binsnitch.py, a tool that creates a baseline file with the md5/sha256/… hash of every file you wish to monitor. In case you think you have a virus, malware or cryptovirus you can verify easely what files have been changed. This is kinda fun, the […]

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I have not found easy explanation on what kind of error states are in Rocks, Grid Engine, so I am collecting them here as I find them. Show states First let’s find the overview of the nodes; this can be done using qstaf -f qstat -f Result should be something like : # qstat -f […]

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In the previous article on Bareos, we setup a quick and dirty backup job to run every night. This was pretty easy, but it has some flaws. (1) the first flaws, -after a full backup- only increment backups are created, forever. This makes it difficult to get a restore going down the line, as all the […]

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I hit upon this error : Cannot open your terminal ‘/dev/pts/0’ – please check. after being logged in under root and su to a user profile; su user and then willing to resume a screen : # screen -r copy.pid Cannot open your terminal ‘/dev/pts/3’ – please check. The issue is resolved using : script /dev/null I previously had similar issues, but […]

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When installing apcupsd on proxmox (similar to centos) I received this error : Error contacting apcupsd @ localhost:3551: Connection refused When running apcaccess. I got more info on the error using checking the service status : root@rocky:~# service apcupsd status ● apcupsd.service – LSB: Starts apcupsd daemon Loaded: loaded (/etc/init.d/apcupsd) Active: active (exited) since Thu 2017-05-11 […]

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I found these errors today in my the cron log : /var/log/cron  May 10 09:53:01 sysadmin CROND[2267]: (librenms) CMD ( /opt/librenms/alerts.php >> /dev/null 2>&1) May 10 09:54:01 sysadmin crond[63]: (root) BAD FILE MODE (/etc/cron.d/librenms.cron) I wrongly assumed a 755 permission was needed for crons, seems I was wrong. For cron execution we only need 644. Surprisingly […]

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SNMP OID to Text

4 May, 2017

I have been searching high and low for this, and it’s not even the first time. Since my brain did not store this long term; I’m sharing it here. When extending snmpd like this : (in /etc/snmp/snmpd.conf) extend zfs-arcstat /usr/bin/cat /proc/spl/kstat/zfs/arcstats The output can be queried using : NET-SNMP-EXTEND-MIB::nsExtendOutputFull.”zfs-arcstat” “zfs-arcstat” is a free to chose name. […]

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ZFS quota

19 April, 2017

ZFS is loaded with useful features, just a while ago I took a peak at setting quotes. Using just a few commands you limit the amount  of storage a certain pool can take. First let’s check if there is no quota set : zfs get quota This would result in something like : # zfs […]

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One of those things I never spend much time on was reading about NFS. There is no need for it, it just kinda works out the box. Most of the time that is. The headache starts when it stops working, or pushes your cluster to a grind. One of the first resources you will find […]

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ZFS replace a broken disk

28 March, 2017

After a reboot, I got greeted with this error : root@server:~# zpool status pool: rpool state: DEGRADED status: One or more devices could not be used because the label is missing or invalid. Sufficient replicas exist for the pool to continue functioning in a degraded state. action: Replace the device using ‘zpool replace’. see: http://zfsonlinux.org/msg/ZFS-8000-4J […]

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