sysadmin

Archiving And Backup

sysadmin

Compression algorithms # Lossless Preserves all data contained in the original. Lossy Removes data as compression is performed to allow more compression. Restored file is a close approximation. (e.g. jpeg, mp3) See also # tar gzip rsync

Climbing Out Of The Hole

sysadmin

Successful teams do these 2 things: Track and organize work in progress (WIP) Eliminate 2 biggest time sinkholes: Operating System (OS) installation Software deployment Turn things around by doing the following: Track and control WIP Automate OS installation Adopt CI/CD for software pushes Outside of Jeff’s oneliners, MH failed in this area. We probably could have automated common software deploys with something like Ansible. ...

dnf

linux, sysadmin, rhel

dnf # Query repos and rpm db # List repositories verbosely: dnf repolist -v List all available packages from all repos: dnf repoquery List all installed packages: dnf list installed List all installed packages and packages available for installation: dnf list List all available updates: dnf list updates Install packages # Install a package: dnf install package Install a package from an RPM: dnf localinstall /path/to/rpm Update a package: ...

File Permissions

linux, sysadmin

File Permissions # File Types # Attribute File Type - A regular file d Directory l Symbolic link c Character special file (streams of bytes like /dev/null) b Block special file (handles data in blocks like HDD or DVD) Examples # Regular file: [root@server1 ~]# ls -l anaconda-ks.cfg -rw-------. ...

Homelab

sysadmin, learning

Homelab # Resources # r/homelab wiki DIY Pegboard Home Network Wall Virtualization # 20230305105049-proxmox IaC # 20230305104932-terraform

Job Scheduling

linux, sysadmin

Job Scheduling # Job scheduling and execution is taken care of by two service daemons: at (1) - queue, examine, or delete jobs for later execution atd (8) - run jobs queued for later execution cron (8) - daemon to execute scheduled commands crond (8) - daemon to execute scheduled commands [root@server1 ~]# ls -ld /etc/{at,cron}* -rw-r--r--. 1 root root 1 Apr 4 2022 /etc/at.deny drwxr-xr-x. 2 root root 21 Feb 16 09:08 /etc/cron. ...

Lightweight Directory Access Protocol

security, sysadmin

LDAP # Lightweight Directory Access Protocol (LDAP) Used to query and change a database used by the network. Protocol: TCP, UDP Port: 389 Windows Active Directory is a common implementation of LDAP. Every Windows domain controller stores a copy of the Active Directory database. LDAP is used to keep all the databases synchronized. LDAPS # LDAP over SSL Port: 636 Resources # Wikipedia - LDAP Wikipedia - List of LDAP software