When a file system is 100% full and has no available space, it cannot increase its metadata structures to point to new space. This is generally true of all file systems. UFS deals with this by creating a dummy file that you can delete if this condition occurs. In version 3.5, Veritas file system adjusted its allocation policies to retain some free space, even when it reports the system is 100% full. However, this allocation policy had a crucial limitation: it did not work if the file system was an exact multiple of the Allocation Unit (AU) size. This size is typically 2^25, but can also be 2^26, 2^27, or 2^28.

Veritas recommends that you address the issue in one of the following ways:

• Upgrade your product to version 5.1 or higher; for example, Storage Foundation 5.1. In version 5.1, the file system team added an enhancement for free space handling. In versions 5.1 and later, you should not see this issue.
  
  
• Resize the file system so that it is either:
  
  
  • Larger than the multiple of 32 KB file system blocks.
    
    For example, if your file system is 32768 KB, it contains 1024 32 KB blocks. Resize the file system to x KB where 32768 < x < 65536.
    
    
  • Less than the multiple of 32 KB blocks minus 68 KB file system blocks.
    
    For example, if your file system is 32768 KB in size, it contains 1024 32 KB blocks. Resize the file system to less than 32768 - 68 = 32700 KB.
    
    
• Create a 64 K placeholder file in the lost+found directory on the mounted file system.
  
  When the file system is 100% full, delete the placeholder file and extend the file system. To create the placeholder file, use the following command:
  
  dd if=/dev/zero of=DELETE_ONLY_WHEN_FS_FULL_TO_AVOID_FS_RESIZING_PROBLEM bs=64K count=1