关于扩容存储后未调整文件系统（filesystem）大小的影响咨询

Hey Alan, let's break down your question in plain terms:

• 最直接的结果：你确实用不上新增的存储空间
  Think of your storage device like a closet you just expanded—you've made the physical space bigger (which lsblk detects), but the shelf inside (that's your filesystem) hasn't been extended to fill the new area. df only sees the space the shelf can hold, so that extra empty space in the closet will just sit there unused. You won't be able to save new files to it, and any attempt to use more space than the original shelf size will hit a "disk full" error.

• 现有数据不会受到损坏
  Leaving the filesystem unresized doesn't put your existing files at risk. The unused raw space is completely separate from the active filesystem, so all your current data stays safe and accessible as normal.

• 会持续带来工具显示不一致的困惑
  You'll keep seeing mismatched numbers between df and lsblk, which can get confusing over time. For example, you might glance at lsblk and think you have plenty of free space, only to find df says you're out of room when you try to save something.

If you later decide to resize the filesystem, the process is straightforward depending on your filesystem type:

• For ext4 filesystems, use the resize2fs command
• For XFS filesystems, use xfs_growfs

Just remember to back up important data first (though resizing is generally low-risk) and follow the steps tailored to your operating system.

备注：内容来源于stack exchange，提问作者Alan Chen