No space left on device in XFS filesystem with 2.4T

Description of the situation:

Recently, colleagues feedback a problem: In a large partition (24T) using the XFS file system, used for historical file backup, suddenly prompted no disk space error, first check the following:

[[email protected] ~]# df-htfilesystem Type Size used Avail use% mounted on/dev/sdb1 xfs 19T 16T 2.4T               88%/backup[[email protected] ~]# df-hifilesystem inodes iused IFree iuse% mounted ON/DEV/SDB1 9.3G 3.4M 9.3G 1%/backup

You can see that, whether it is physical space, or inode, there is a lot of headroom, then why do you report disk space is not enough?

The following XFS FAQ was queried and found a section:

Q:What is the inode64-mount option for?

By default, with 32bit inodes, XFS places inodes only in the first 1TB of a disk. If you had a disk with 100TB, all inodes would be stuck in the first TB. This can leads to strange things like "disk full" If you still has plenty space free, but there's no more place in the F Irst TB to create a new inode. Also, Performance sucks.

To come around this, use the Inode64 mount options for filesystems >1TB. Inodes'll then being placed in the location where their data is, minimizing disk seeks.

Beware that some old programs might has problems reading 64bit inodes, especially over NFS. Your Editor used inode64 for over a year with recent (OpenSUSE 11.1 and higher) distributions using NFS and Samba without Any corruptions, so-might be a recent enough distro.

The idea is that the XFS filesystem will store the inode in the 1T space at the beginning of the disk, and if that space is fully populated, then there will be a lack of disk space error hints.

To see the man help manual for Mount, you can see the following:

Inode64

Indicates that XFS was allowed to create inodes at any location in the filesystem, including those which would result in Ino De numbers occu-pying more than, bits of significance. This was provided for back-wards compatibility and causes problems for backup applications that

Cannot handle large inode numbers.

The workaround is to specify the INODE64 option when mounting:

Mount-o Remount-o Noatime,nodiratime,inode64,nobarrier/dev/sdb1/backup

Reference: https://www.centos.org/forums/viewtopic.php?t=21766

P.S: Disk space less than 1T do not worry about this problem.

This article is from the "Frozen vs watermelon" blog, so be sure to keep this source http://molewan.blog.51cto.com/287340/1703109

No space left on device in XFS filesystem with 2.4T