thinQmaster Virtual testing partner Adaptive practice exams that find your weak spots and drill them. Every answer explained. From $69
Enroll

thinQmaster

Find your exam

Five questions free, before you decide.

Step 1 · choose a vendor

In one of our camps? Your practice exams come with the tuition — they are on your study page already.

Systems & Data Center · Foundational

ext4

The fourth extended filesystem, a mature journaling filesystem that is the default on many Debian and Ubuntu Linux systems.

Definition

ext4 supports volumes up to 1 EiB and files up to 16 TiB (with 4 KiB blocks), uses extents for efficient allocation, and journals metadata for fast crash recovery. It can be grown online and shrunk offline using resize2fs.

Example

mkfs.ext4 /dev/vg01/lv_data formats a logical volume as ext4.

Exam tip

ext4 can be shrunk (offline) but XFS cannot be shrunk at all, a frequent comparison question.

Related terms