LPI Linux Essentials case studies
LPI Linux Essentials · Put your knowledge to work in context.
Linux Essentials is LPI's entry-level, vendor-neutral certificate for people who want to show a solid foundation in working with a Linux system and open source applications. The source describes it as a great introduction to the more complete Linux Professional track, and notes that educational institutions often combine the exam with their own programs. The LPI Linux Essentials case studies are 5 cases and about 3,798 words.
1Shipping a NAS appliance with mixed open-source components
Northwind Storage ships a 2U NAS appliance built on Linux 6.6. Four components are in the image: (a) nwfs.ko, a custom kernel module that calls register filesystem and uses symbols exported with EXPORT SYMBOL GPL; (b) nwmgmtd, a closed-source userspace daemon that talks to nwfs.ko over a netlink socket; (c) a patched GRUB 2.12 with a custom theme, used in the signed UEFI boot chain; (d) BusyBox 1.36.
739 words, about 4 min2A misleading 404 top-talkers pipeline on a 4 GB nginx log
An nginx access log at /var/log/nginx/access.log is 4.1 GB and 2.4 million lines in combined log format. A typical line begins: 10.0.0.5 - - [12/Mar/2024:10:00:00 +0000] GET /missing HTTP/1.1 404 153 - curl/7.68.
776 words, about 4 min3CSV revenue totals broken by BOM, CRLF and quoted commas
finance exports a 380 MB CSV named sales.csv with header region,product,units,revenue and about 1.1 million rows. Product names can contain commas inside double quotes, for example a product called Widget, large, and embedded double quotes are escaped by doubling, for example a product called 12-inch screen written with doubled quotes.
775 words, about 4 min4ENOSPC with free blocks, exhausted inodes and a deleted open file
At 03:10 a monitoring alert fires for an Ubuntu 22.04 database host. Applications report 'No space left on device'.
725 words, about 4 min5Shared finance directory, default ACLs and a setuid import script
On an Ubuntu 22.04 file server, /srv/finance is owned root:finance, mode 2775. Users alice, bob and carol are members of finance and nothing else.
783 words, about 4 min