sendmail, 4th Edition

SFS_TYPE

How to determine free disk space Port, edit sendmail/conf.h

The sendmail program can temporarily fail incoming mail messages if they are too large for the queueing disk. This ability is enabled by giving a positive, nonzero size to the MinFreeBlocks option (Milter.macros.envrcpt on page 1055). The method sendmail uses to measure the free space on a disk varies from system to system. This SFS_TYPE compile-time macro defines which of several methods sendmail will use. Those available are shown in Table 3-11.

Table 3-11. Method to determine free disk space

Compile-time macro	Description
SFS_NONE	Your system has no way to determine the free space on a disk. This causes the MinFreeBlocks option (MinFreeBlocks on page 1057) to be ignored.
SFS_USTAT	Your system uses the ustat(2) system call to get information about mounted filesystems.
SFS_4ARGS	Your system uses the four-argument form of the statfs(2) system call and <sys/statfs.h>. If you define this, you can also define SFS_BAVAIL as the field name for the statfs C-language structure (by default, f_bavail).
SFS_VFS	Your system uses the two-argument form of the statfs(2) system call and <sys/vfs.h>.
SFS_MOUNT	Your system uses the two-argument form of the statfs(2) system call and <sys/mount.h>.
SFS_STATFS	Your system uses the two-argument form of the statfs(2) system call and <sys/statfs.h>.
SFS_STATVFS	Your system uses the statvfs(2) system call.

In general, SFS_TYPE is correctly defined for all supported systems. ...