File Systems & Storage Management Flashcards

Which command checks and repairs an XFS filesystem that is NOT currently mounted?

Answer: xfs_repair /dev/sdc1

xfs_repair is the correct tool to check and repair an unmounted XFS filesystem.

What does 'pvmove /dev/sdb' accomplish in LVM?

Answer: Migrates all LV data off /dev/sdb to other PVs in the VG

pvmove relocates physical extents from one PV to other available PVs within the same volume group.

In a Btrfs filesystem, what is a 'subvolume'?

Answer: An independently mountable POSIX file tree within a Btrfs volume

A Btrfs subvolume is an independently snapshotted and mountable file tree namespace within a single Btrfs volume.

Which command shows real-time disk I/O statistics per device, including read/write throughput?

Answer: iostat -xz 1

iostat -xz 1 reports extended device statistics every second, showing throughput, utilization, and I/O wait.

What does the 'discard' mount option enable for SSDs?

Answer: Continuous TRIM support to inform the SSD of freed blocks

The discard option sends TRIM commands to the SSD whenever blocks are freed, maintaining SSD performance over time.

Which field in /etc/fstab specifies the order in which fsck checks filesystems at boot?

Answer: Sixth field (fs_passno)

The sixth field (fs_passno) determines fsck check order; root is typically 1, other filesystems 2, and 0 means skip.

What is the maximum single file size supported by a default FAT32 filesystem?

Answer: 4 GB minus 1 byte

FAT32 uses a 32-bit file size field, limiting individual files to 4 GB - 1 byte (4,294,967,295 bytes).