jfs_mkfs

jfs_mkfs [ -c ] [ -J journal_device ] [ -j journal_size ] [ -L volume_label ] [ -q ] [ -r ] [ -s block_size ] [ -v ] [ -V ] [ -z stripe_unit_size ] device

-c
    Checks the device for bad blocks before creating the filesystem.

-J journal_device
    Specifies an external device to be used for the JFS journal.

-j journal_size
    Sets the size of the internal journal in megabytes. The default is 32MB.

-L volume_label
    Assigns a volume label to the filesystem, up to 16 characters.

-q
    Operates in quiet mode, suppressing most output.

-r
    Performs a read-only check of the device. This option does not create a filesystem.

-s block_size
    Sets the block size of the filesystem in bytes (512, 1024, 2048, or 4096). Default is 4096 bytes.

-v
    Operates in verbose mode, showing more detailed progress information.

-V
    Displays the version information for jfs_mkfs and exits.

-z stripe_unit_size
    Specifies the stripe unit size in bytes for RAID configurations, influencing data allocation.

device
    The block special device (e.g., /dev/sdb1) on which to create the JFS filesystem. This is a mandatory argument.

The jfs_mkfs command (also invoked as mkfs.jfs) is used to construct a Journaled File System (JFS) on a specified block device. JFS is a robust and high-performance journaling filesystem developed by IBM, initially for its AIX operating system and later ported to Linux.

When jfs_mkfs is executed, it initializes the device by creating the necessary JFS metadata structures, including the superblock, inode maps, and allocation maps. This process irrevocably erases all existing data on the target device. The command offers various options to customize the filesystem creation, such as specifying block size, setting a volume label, checking for bad blocks, or configuring an external journal. JFS's journaling capabilities ensure data integrity and faster recovery after system crashes or power failures by logging changes before they are committed to the main filesystem.

Data Loss: Using jfs_mkfs will permanently erase all data on the specified device. Ensure you have backed up any critical information before proceeding.
Root Privileges: This command typically requires superuser (root) privileges to operate on block devices.
Journaling: JFS is a journaling filesystem. While an internal journal is created by default, understand the implications if you choose to use an external journal or specify a custom size.
Block Size: Choosing an inappropriate block size (with -s) can impact performance or storage efficiency, depending on the typical file sizes stored on the filesystem.

Returns 0 on success, 1 on a read-only check that failed, or 2 on failure.

To create a JFS filesystem on /dev/sdb1 with a volume label "MY_JFS_DISK":
sudo jfs_mkfs -L MY_JFS_DISK /dev/sdb1

Journaled File System (JFS) was originally developed by IBM for its AIX operating system in the early 1990s. The first version, JFS1, was designed for high-performance servers. JFS2 (also known as JFS on Linux) was introduced later, bringing enhanced features and scalability.

The Linux port of JFS2 was initiated by IBM developers and became part of the mainline Linux kernel in 2001. While it offers a robust and mature journaling solution, JFS is less commonly used on Linux compared to filesystems like Ext4, XFS, or Btrfs. Despite this, it remains a fully supported and stable option for specific use cases or environments preferring its design characteristics.

jfs_fsck(8), jfs_tune(8), mount(8), fstab(5), mkfs(8)