CentOS文件系统类型有哪些

Common File System Types in CentOS

1. ext4 (Fourth Extended File System)

ext4 is a journaled file system developed as the successor to ext3, optimized for Linux environments. It improves upon ext3 with enhanced data structures, supporting larger file systems (up to 1 EB) and individual files (up to 16 TB). ext4 is backward compatible with ext3 and ext2, making it a reliable choice for general-purpose storage (e.g., daily file storage, website data). It was the default file system for CentOS 6.x and remains widely used in later versions for its stability.

2. ext3 (Third Extended File System)

ext3 is a journaled file system that extends ext2 by adding journaling capabilities, which improve reliability by logging changes before committing them to disk. This reduces the risk of file system corruption during sudden power loss or system crashes. ext3 supports file systems up to 16 TB and files up to 2 TB. It was the default file system for CentOS 5.x and is still used in legacy systems requiring compatibility with older hardware.

3. ext2 (Second Extended File System)

ext2 is a non-journaled file system that was the standard for early Linux distributions. While it offers fast performance for small to medium files, it lacks journaling, making it more vulnerable to data loss in case of unexpected shutdowns. ext2 is gradually being replaced by ext3 and ext4 but may still be found in older systems or embedded devices with limited resources.

4. tmpfs (Temporary File System)

tmpfs is a memory-based file system that uses RAM (and optionally swap space) for storage. Unlike traditional block devices, tmpfs does not require formatting—it is mounted directly into the file system hierarchy. It is ideal for temporary data (e.g., /tmp directories, session data) because it provides faster access speeds than disk-based file systems. However, its contents are lost when the system reboots.

5. cramfs (Compressed ROM File System)

cramfs is a compressed read-only file system designed for embedded systems with limited storage. It does not decompress the entire file system into memory at once; instead, it decompresses data on-demand when accessed. This reduces memory usage while maintaining fast read performance. cramfs is suitable for storing firmware, bootloaders, or other static data that does not require modification.

6. xfs (XFS File System)

xfs is a high-performance journaled file system developed by SGI. It is optimized for handling large files and file systems (up to 8 EB) and excels in parallel I/O operations, making it ideal for virtualization, database storage, and media workloads. xfs was introduced in CentOS 7 as the default file system, replacing ext4 for its superior scalability and recovery features (e.g., fast crash recovery, online defragmentation).

7. btrfs (B-tree File System)

btrfs is a modern copy-on-write (CoW) file system that introduces advanced features like snapshots, data integrity checking, and compression. It is designed for enterprise environments requiring high availability and data protection. btrfs supports dynamic volume management and can handle large-scale storage pools. While it was introduced in CentOS 7, it may not be enabled by default in all versions, and users should verify compatibility before adoption.

8. swap (Swap Partition)

swap is a special file system used as virtual memory when physical RAM is exhausted. It allows the system to temporarily store inactive pages of memory on disk, freeing up RAM for active processes. The size of a swap partition is typically recommended to be 1–2 times the amount of physical RAM (up to a maximum of 2 GB). swap is essential for preventing out-of-memory errors in systems with limited RAM.

9. Network and Special File Systems

CentOS supports various non-native file systems for specific use cases:

NFS (Network File System): Enables file sharing between Linux/Unix systems over a network.
iso9660: The standard file system for CDs/DVDs, allowing CentOS to read optical media.
vfat/fat32: Compatible with Windows file systems, enabling access to FAT-formatted drives (e.g., USB sticks).
NTFS: Supports Windows NTFS partitions (read/write with additional drivers like ntfs-3g).
proc/sysfs: Virtual file systems that expose kernel and system information (e.g., /proc for process data, /sys for hardware configuration).