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@wmealing
wmealing / C-states.md
Last active May 17, 2024 07:53
What are CPU "C-states" and how to disable them if needed?

To limit a CPU to a certain C-state, you can pass the processor.max_cstate=X option in the kernel line of /boot/grub/grub.conf.

Here we limit the system to only C-State 1:

    kernel /vmlinuz-2.6.18-371.1.2.el5 ... processor.max_cstate=1

On some systems, the kernel can override the BIOS setting, and the parameter intel_idle.max_cstate=0 may be required to ensure sleep states are not entered:

@mac2000
mac2000 / postgres_master_slave_failover_failback.md
Last active June 28, 2024 08:23
Postgres Master Slave Failover & Failback

Postgres Master Slave Failover & Failback

video

start

docker run -it --rm -p 5551:5432 --name=db1 --hostname=db1 ubuntu:20.04 bash
docker run -it --rm -p 5552:5432 --name=db2 --hostname=db2 ubuntu:20.04 bash

Proxmox with LVM-thin and why we should use Trim/Discard

Excerpts from the Proxmox VE Administration Guide]

LVM normally allocates blocks when you create a volume. LVM thin pools instead allocates blocks when they are written. This behaviour is called thin-provisioning, because volumes can be much larger than physically available space.

8.10.2. Trim/Discard It is good practice to run fstrim (discard) regularly on VMs and containers. This releases data blocks that the filesystem isn’t using anymore. It reduces data usage and resource load. Most modern operating systems issue such discard commands to their disks regularly. You only need to ensure that the Virtual Machines enable the disk discard option.

@joelonsql
joelonsql / PostgreSQL-EXTENSIONs.md
Last active July 24, 2024 14:32
1000+ PostgreSQL EXTENSIONs

🗺🐘 1000+ PostgreSQL EXTENSIONs

This is a list of URLs to PostgreSQL EXTENSION repos, listed in alphabetical order of parent repo, with active forks listed under each parent.

⭐️ >= 10 stars
⭐️⭐️ >= 100 stars
⭐️⭐️⭐️ >= 1000 stars
Numbers of stars might not be up-to-date.