OS - File System
macOS/iOS: APFS, Apple File System
- replaces HFS+
- optimized for flash and solid-state drive storage, with a primary focus on encryption
- APFS supports 64-bit inode numbers, supporting over 9 quintillion files on a single volume
- Windows 10: NTFS
- Red Hat/CentOS: XFS
$ df -Th
You may find other filesystem like:
- tmpfs: a common name for a mounted file system, but stored in volatile memory instead of a persistent storage device
- drvfs: mounted Windows disks, seen in Windows Subsystem for Linux (WSL). e.g.
FUSE: Filesystem in Userspace. The interface that lets non-privileged users create their own file systems without editing kernel code; a "bridge" to the actual kernel interfaces. E.g. GlusterFS, GmailFS.
/var: contains files to which the system writes data during the course of its operation.
- /var/cache (contains cached data from application programs),
- /var/games (contains variable data relating to games in /usr),
- /var/lib (contains dynamic data libraries and files),
- /var/lock (contains lock files created by programs to indicate that they are using a particular file or device),
- /var/log (contains log files),
- /var/run (contains PIDs and other system information that is valid until the system is booted again) and
- /var/spool (contains mail, news and printer queues).
/usr is for software built elsewhere and then installed on the machine (mostly from your distributions package management system)
/usr/local is for software built locally
$ cat /proc/partitions major minor #blocks name 253 0 31457280 vda 253 16 62914560 vdb 253 32 65536 vdc 253 48 251658240 vdd
file -s <device> to check type
$ sudo file -s /dev/vda /dev/vda: Linux rev 1.0 ext4 filesystem data, UUID=6f54f78f-3f47-488c-ab1b-b1b8a596c2d3, volume name "c3image-rootfs" (needs journal recovery) (extents) (large files) (huge files)