How to Format a Disk with UFS on FreeBSD Operating System

Formatting a disk with the Unix File System (UFS) on FreeBSD is a common task for system administrators and users who need a robust and reliable filesystem. UFS is the traditional filesystem used in BSD-based systems, known for its performance, stability, and advanced features like soft updates and snapshots. This guide will walk you through the step-by-step process of formatting a disk with UFS on FreeBSD.

Prerequisites

Before proceeding, ensure you have:

• A FreeBSD system with root or superuser privileges.
• A disk that you want to format.
• Basic knowledge of FreeBSD’s command-line interface.

Step 1: Identify the Target Disk

To prevent accidental data loss, correctly identifying the target disk is crucial. Use the following command to list all available disks:

ls /dev/da*

Alternatively, you can use:

gpart show

This command will display partition information for all connected disks. Identify the correct disk based on its size and partition layout. Assume the target disk is /dev/da1 for this guide.

Step 2: Unmount the Disk (if necessary)

If the disk is mounted, unmount it before formatting:

umount /dev/da1

To check if the disk is mounted, use:

mount | grep da1

Step 3: Wipe Existing Partition Table (if needed)

If the disk has existing partitions, clear them with:

gpart destroy -F da1

To ensure the disk is completely clean, you can also zero out the first few sectors:

dd if=/dev/zero of=/dev/da1 bs=1M count=10

Step 4: Create a New Partition Table

Use gpart to create a new partition table. Here, we use GPT (GUID Partition Table):

gpart create -s gpt da1

For an MBR partition scheme, use:

gpart create -s mbr da1

Step 5: Create a UFS Partition

Next, create a partition for UFS. Typically, you allocate the entire disk:

gpart add -t freebsd-ufs -a 1M -l mydisk da1

• -t freebsd-ufs specifies the UFS type.
• -a 1M aligns the partition for better performance.
• -l mydisk assigns a label to the partition.

Step 6: Format the Partition with UFS

Once the partition is created, format it using the newfs command:

newfs -U -L myufs /dev/da1p1

• -U enables soft updates, improving filesystem consistency.
• -L myufs assigns a label to the filesystem.

If you need journaling (for better recovery options), use:

newfs -j -L myufs /dev/da1p1

For UFS2, which is commonly used:

newfs -O2 -U -L myufs /dev/da1p1

Step 7: Mount the New Filesystem

Create a mount point and mount the new UFS filesystem:

mkdir /mnt/myufs
mount /dev/da1p1 /mnt/myufs

To verify:

df -h

Step 8: Configure Auto-Mounting (Optional)

To ensure the filesystem mounts automatically at boot, add an entry to /etc/fstab:

echo "/dev/ufs/myufs /mnt/myufs ufs rw 1 1" >> /etc/fstab

Alternatively, if you prefer mounting by device name:

echo "/dev/da1p1 /mnt/myufs ufs rw 1 1" >> /etc/fstab

Step 9: Verify the Filesystem

To check the filesystem for errors, use:

fsck -y /dev/da1p1

You can also inspect filesystem details with:

tunefs -p /dev/da1p1

Step 10: Unmounting the Filesystem (if needed)

If you need to unmount the filesystem:

umount /mnt/myufs

To ensure no process is using the filesystem, run:

fstat | grep da1p1

Conclusion

Formatting a disk with UFS on FreeBSD is a straightforward process once you understand the required steps. By carefully identifying the disk, creating partitions, and applying the correct UFS settings, you ensure an efficient and reliable storage setup. Whether you use UFS1 or UFS2, enabling features like soft updates and journaling can enhance performance and resilience. Following this guide, you can confidently format and manage disks with UFS on FreeBSD.