Shrinking OS image manually

Recently I needed to customize the OS template used to deploy KVM guests and once it was ready I realized it could be a lot smaller – there was plenty of free space on the partition which made the image larger than necessary, therefore I decided to reduce the size to the minimum possible and while it could be done via tools such as GParted – I couldn’t miss the opportunity to explore how it’s… Read More »Shrinking OS image manually

A few words about Bash scripting

Bash is… the middle man between the user and the system. I’ve been scripting in Bash for more than 20 years and I can’t imagine doing sysadmin tasks without it. I used to say “You don’t need to be a sysadmin to learn Bash but you’re not sysadmin without advanced Bash skills”. I’ve met a lot of sysadmins on my path, some were less experienced than others but all of them were scripting in Bash… Read More »A few words about Bash scripting

Expanding OS partition – LVM on top of MD RAID – without downtime

Expanding OS partition – LVM on top of MD RAID – without downtime   Replacing failing physical disks on the servers hosted at the data center could be just another routine task with no surprises.  Sadly, it’s often a headache since you need to rely on DC support and there’s no way to tell if the person on the other end is newly hired and still learning, or maybe is distracted? or simply doesn’t care… Read More »Expanding OS partition – LVM on top of MD RAID – without downtime

Static compilations with musl standard library – great alternative to glibc

Static compilations with musl standard library – great alternative to glibc.     Building statically linked tools with glibc is real pain, compiled executables are big but there’s no room for complaints, you’re lucky if it successfully compiled. I’ve been following the musl project for some time already – musl manages to address all the issues with static linking, where Glibc is lacking. It’s superior in every way.   For now, musl is the clear… Read More »Static compilations with musl standard library – great alternative to glibc

KVM guests – compressed storages – enabling TRIM support on virtio disks

Trim is commonly used as a way to notify SSD drive that some part of the data it holds is garbage and can be discarded, it extends SSD lifetime and releases otherwise reserved space on the disk. Turns out it’s not the only scenario where trim comes handy. Compression is a popular way to save on space usage when deploying virtual machines and it seems to be a good option especially that the performance penalty… Read More »KVM guests – compressed storages – enabling TRIM support on virtio disks