PRIMECLUSTER Global File Services Configuration and Administration Guide 4.1 (Linux)

1.8.7 Open processing from other nodes to a file mapped by mmap(2)

Do not perform the following operation in GFS Shared File System.

• open(2) and creat(2) from other nodes to a file mapped by mmap(2)

If open(2) and creat(2) is executed from other nodes to a file mapped by mmap(2), the system call will fail to assure the data consistency.

• open(2) and creat(2) from other nodes to a mmap(2) file for which PROT_WRITE and MAP_SHARED are specified.
• open(2) and creat(2) with the write mode from other nodes to a mmap(2) file for which PROT_READ and MAP_SHARED are specified.

If creat(2) and open(2) with O_TRUNC is executed in the above-mentioned operation, the system call will fail and the target file will be truncated to length zero.