Analysis of Linux Filesystems – How to Compare Ext3, Ext4, Btrfs and XFS
Linux offers numerous filesystems, there’s little speed gain between them, but they are each optimised for a different task. Here we compare each system.
Journaling > Faster than Ext2 > Meta-data journaling
Negatives: FScheck is slow > Max filesize is 2 TB > Max Volume Size is 16 TB > The limits are bad for data centres > Max number of Sub Directories is 32,000 > No Delayed Allocation > No Snapshots > No encryption > No Clones > No Compression > No Deduplication > No Integrated LVM.
2. Ext 4
Delayed Allocation = Minimises Fragmentation > Extends = Large file performance > No limit on number of Sub Directories > Journal uses Checksums for reliability > Backward compatible with Ext3 and Ext2 > Meta-data Journaling
Negatives: Theodore Ts’o considers Ext filesystems as 1970’s technology and would prefer Btrfs > Max filename length 255 > Max file size is 16 TB > Max Volume size is 1 EB > No Snapshots > No Clones > No Encryption > No Compression > No Deduplication > No Integrated LVM
Copy on Write filesystem > Built in Volume Manager > RAID Support for 0/1/5/6/10 > Checksums for data integrity > Copy on Write means all or nothing is written to disk. Self healing using copies > supports Snapshots > SSD aware > Supports TRIM wear levelling block discard > Max filelength name is 255 > Max file size is 8 EB (Linux kernel limit) > Max volume size is 16 TB > Clones supported > Compression > Deduplication > Integrated LVM
Future plans include: In-Band Deduplication, improved on/offline filesystem checks, encryption, swap partitions, incremental backups.
Negatives: Relatively new, not tried and tested > features lead to minor performance penalties. No Meta-data journaling > no Encryption
64 bit Journaling system > Stable > Handles large filesystems > Max file size is 8 EB (Linux kernel limit) > Max volume size is 16 EB > max filename length is 255 > Delayed Allocation > Meta-data journaling.
Negatives: No Snapshots, no encryption, no compression, no deduplication.