yum history

On RHEL/CentOS, yum history is not well-known but is a nice way to undo package installs, including dependencies, or updates. Usage is self-explanatory. I provided some examples below: If you really want you can undo […]

Visual Studio Code – Edit Multiple Lines

Visual Studio Code is a free and awesome editor from Microsoft for Mac, Windows and Linux. I recently discovered that you can select multiple lines at the same time. I was missing this coming from […]

Easy SSH On macOS

Using public key authentication for ssh is safer than password. But you should really use a passphrase protected private key. Now you are safe but you still need to type in your passphrase. This isn’t […]

Delete a Single Line From History

Did you ever wanted to remove a single line from your shell history? This is how you can easily do it: use: history -d line number to remove the line, for example history -d 431, […]

A Magic Trick From ZFS

This is a short description about how to recover a single or multiple files from a ZFS snapshot on FreeBSD. The same trick might work on Linux, I haven’t tried, if you did please let […]

How’s YOUR server doin’?

If you are using FreeBSD then you must be familiar with daily run output or daily security run output messages. They can be found in the root user’s mailbox by simply typing mail as root. If you’re […]

Random vSphere Disconnection Issues

There is a setting in vSphere/ESXi called NFS.MaxQueueDepth. Starting ESXi 5.x the default value is 4294967295. However some storages are not happy with this and when traffic increases (I’m not sure how much traffic is too much) […]

vCenter “Unable to retrieve manifest or certificate file”

There is a bug in vCenter 6.5 which occasionally happens when you deploy an OVA from web. VMware is probably going to fix it, but until then when need to use a workaround. OVA file […]

zfs allow

By default many zfs operations needs elevated/root privileges. For example receiving a snapshot on a remote system. One does not want to open ssh to root user. With zfs allow permissions can be delegated to […]

Mikrotik Script

mikrotik

Here is simple script which sends your IP address to your email, it will save you paying for a fix IP service from your ISP, unless you have a different case. :global ipadd; :global extinterface […]