Author Archive

AppLocker blocking Logon scripts

I ran into an issue today on Windows Server 2012R2 where AppLocker was blocking logon & logoff scripts despite the sysvol folder being in the allowed policy. The documentation indicates that allowing the following folder should be enough: \\domain.com\sysvol\domain.com\policies\* This isnt the case, you actually need the NETLOGON folder too: \\domain.com\NETLOGON\* And in my instance […]

Clear ARP on various systems

Just a quick reference for how to clear ARP entries on various systems following a network change: Windows Print arp table: arp -a Delete single entry: arp -d 192.168.1.1 Delete entire arp table: arp -d * Add static entry: arp -s 192.168.1.1 00-aa-00-62-c6-09 Cisco ASA/IOS/NX-OS Print arp table: show arp Delete entire arp table: clear […]

ESXi won’t boot from USB stick

I was installing ESXi 5.5 onto a USB stick today, something I have done hundreds of times. The install went fine, however no matter what I tried in the bios it just wouldn’t boot. Turns out, the server (in this case a HP DL380 G8) had no support for UEFI. Since ESXi5.5 installs as GPT […]

Veeam as a vSphere backup solution

I’ve recently had the pleasure of implementing Veeam Backup & Replication v8 as a direct replacement for BackupExec 2012/2014 vRay edition.  BackupExec 2012 was a terrible product, which is such a shame considering how good its Veritas predecessor was.  BackupExec 2014 was just as bad; its low reliability and poor usability create a huge support […]

Distributed Monitoring in Nagios with check_mk multisite

For some time now, I’ve been exploring the best ways of configuring a distributed Nagios setup. With the “federated” configuration that Nagios recommend, you can pass data from remote Nagios instances back to a central Nagios server with the use of passive checks combined with NSCA or NRDP. Whilst this works well, the duplicate configuration […]

vSphere ESXi firmware & driver alignment

Recently whilst troubleshooting a vSphere cluster issue, I had to align the firmware and driver on each ESXi host in the cluster. The following commands help to gather the required information. Of course you could easily create a PowerCLI script to cycle through each host and run these commands if you are inclined: Bios Version: […]

check_cab Nagios plugin for Hawk-I rack monitoring

If you use Sinetica Hawk-I or RacKMS to manage/monitor your datacentre cabinets, I’ve created a Nagios plugins to monitor each of the sensors (temperature/humidity etc). You can grab check_cab over at Nagios Exchange.

Configuring ESXi network coredump settings

Its useful to configure your VCSA as a network dump collector for when your ESXi hosts experience a PSOD, just make sure that the “ESXi Dump Collector” service is running on your VCSA.  The host configuration via ESXCLI is as follows: esxcli system coredump network set –interface-name vmk0 –server-ipv4 xx.xx.xx.xx –server-port 6500 esxcli system coredump […]

Moving from SysV to Systemd

Goodbye initd, systemd is here!  Systemd brings a lot of benefits such as parallel startups and enhanced troubleshooting but sure does takes some getting used to when you have been working in a completely different way for your entire Linux life!  Systemd is now shipping with CentOS7 and most of the other major distros, so […]

Export Java Keystore Certificate & Private Key to PEM

I always find Java Keystores a total ballache to work with, would rather manage individual PEM files any day of the week. If you need to export the contents for use with something else you can use the following commands: Export from JKS to PKCS #12. keytool -importkeystore -srckeystore oldkeystore.jks -destkeystore cert.p12 -deststoretype PKCS12 -srcalias […]