xfs_info(8)

💖 xfs_info(8) 💖

xfs_info is part of the System Manager's Manual 👑, so this is the official page for it. Let's get into it 🧚✨

🌸 NAME 🌸

xfs_info — display XFS filesystem geometry information 📏

🎀 SYNOPSIS 🎀

xfs_info [ -t mtab ] [ mount-point | block-device | file-image ]
xfs_info -V

✨ DESCRIPTION ✨

okay so xfs_info is how you peek at the geometry of an XFS filesystem that already exists 👀 It tells you how the filesystem is laid out 🗺️

You can point it at a mount-point, which is just the pathname of a directory where the filesystem is mounted 📂 Or you can give it a block-device or file-image, which holds a raw XFS filesystem 💾

Nothing gets touched!! The existing contents of the filesystem stay exactly as they are 🫶 It's read-only vibes only 🧘‍♀️

🦋 OPTIONS 🦋

• -t — pick your own mount table file 🗂️ By default it uses /proc/mounts if that exists, otherwise /etc/mtab. You'd reach for this when you're dealing with filesystems that got mounted without writing to the /etc/mtab file. Check out mount(8) for the deets 📖 Heads up: this one does nothing when you're using the block-device or file-image parameters 🙈
• -V — prints the version number and then exits 🏷️ You don't need a mount-point when you use -V, so skip it 💅

🍓 EXAMPLES 🍓

Let's decode some xfs_info output, bestie 🤓

Suppose one has the following "xfs_info /dev/sda" output:

  meta-data=/dev/pmem0             isize=512    agcount=8, agsize=5974144 blks
           =                       sectsz=512   attr=2, projid32bit=1
           =                       crc=1        finobt=1, sparse=1, rmapbt=1
           =                       reflink=1
  data     =                       bsize=4096   blocks=47793152, imaxpct=25
           =                       sunit=32     swidth=128 blks
  naming   =version 2              bsize=4096   ascii-ci=0, ftype=1
  log      =internal log           bsize=4096   blocks=23336, version=2
           =                       sectsz=512   sunit=0 blks, lazy-count=1
  realtime =none                   extsz=4096   blocks=0, rtextents=0

okay so look at the data section 👀 It says bsize=4096, which means the data block size for this filesystem is 4096 bytes 💖 That's the main thing to catch 🎯

Now the same section also shows sunit=32 swidth=128 blks, and this is giving stripe math 🧮 The stripe unit works out to 32*4096 bytes = 128 kibibytes ✨ The stripe width is 128*4096 bytes = 512 kibibytes 🔥 So one stripe of this filesystem is made up of four stripe units (128 blocks / 32 blocks per unit) 👑 Slay the math 💅

🧚 SEE ALSO 🧚

mkfs.xfs(8), md(4), lvm(8), mount(8) 🌈

bestie, that's the whole page 🫶 The footer just says xfs_info(8) with no version or date listed, so that's all I've got for the source info 💜 Stay iconic and go read some geometry output 🦋💀