This chapter contains an alphabetic list of the following Control Program functions.

• DosAliasMem

• DosCancelLockRequestL

• DosClose

• DosCreateEventSem

• DosCreateThread2

• DosDumpProcess

• DosFindFirst

• DosFindNext

• DosForceSystemDump

• DosGetProcessorStatus

• DosListIO

• DosListIOL

• DosOpen

• DosOpenL

• DosPerfSystemCall

• DosProtectOpenL

• DosProtectQueryFileInfo

• DosProtectSetFileInfo

• DosProtectSetFileLocksL

• DosProtectSetFilePrtL

• DosProtectSetFileSizeL

• DosQueryABIOSSuport

• DosQueryFileInfo

• DosQueryMemState

• Dos16QueryModFromCS

• DosQueryModFromEIP

• DosQueryPathInfo

• DosQuerySysInfo

• DosQuerySysState

• DosQueryThreadAffinity

• DosRead

• DosReplaceModule

• DosSetFileInfo

• DosSetFileLocksL

• DosSetFilePtr

• DosSetFilePtrL

• DosSetFileSizeL

• DosSetPathInfo

• DosSetProcessorStatus

• DosSetThreadAffinity

• Dos16SysTrace

• DosTmrQueryFreq

• DosTmrQueryTime

• DosVerifyPidTid

• DosWrite

The following APIs, from the list above, are Raw File System APIs.

• DosClose

• DosListIO

• DosOpen

• DosRead

• DosSetFilePtr

• DosWrite

The OS/2 raw file system provides an interface for applications to manage data efficiently on the logical partitions or physical hard drives installed in a system. Some of the raw file system function is available by using a combination of the DosPhysicalDisk and DosDevIOCtl application programming interfaces.

The OS/2 raw file system provides a programming abstraction that treats each logical partition or physical disk as one large file that can be opened, locked, seeked, read from, written to, and closed. Logical partitions are identified using the Universal Naming Convention (UNC) in the form of '\\.\X ', where 'X' can be substituted with the letter corresponding the logical partition desired on any hard drive, floppy disk or CD-ROM drive. Physical disks are identified using UNC naming in the form of '\\.\Physical_Disk#', where '#' is replaced with the physical disk number corresponding to the number found in the LVM command. The combination of the naming convention and use of the common file system application programming interfaces (APIs) provides a greatly simplified migration path for applications.

Traditionally, raw file systems have been utilized by applications that manage large amounts of data under heavy workloads. Typically, this has been commercial database servers performing on-line transaction processing. Disk I/O can become a bottleneck under these conditions and the use of an efficient raw file system can be very useful in improving system performance, through reduced path length and serialization.