Removable Mass Storage (RMS)
RMS is a type of device and media that is high capacity, random access, and interchangeable between systems and partitions.
RMS devices and media are similar to optical storage regarding behavior and access interfaces. They are managed and used with existing optical device functions and commands. See Optical storage as a reference guide for use of these devices and media. RMS media are handled the same as optical volumes, and as such are also accessible through the QOPT file system by using the hierarchical file system (HFS) and integrated file system (IFS) APIs. RMS media are formatted with the industry standard Universal Disk Format (UDF) version 2.5.
Two types of RMS devices and media are supported. Removable disk (RDX) cartridges are media that contain a spinning disk. The other is flash drive, which reports as Device Specific Media or *DEVICE mass storage. The media and devices are used as a backup and recovery solution for IBM i systems that can take advantage of the moderate throughput and the lower price of removable disk or flash drives.
RDX devices can be attached with SATA or USB interfaces and can be hosted to a virtual client partition. Devices that report as *DEVICE must be attached to the USB interface and can also be hosted to a virtual client partition.
| Hardware resource type and model | Device type |
|---|---|
| 63B8-004 | RDX SATA |
| 63B8-005 | RDX USB |
| 63B8-0D2 | RDX (virtual client partition) |
| 63BC-005 | Device-specific USB |
| 63BC-0D2 | Device-specific (virtual client partition) |
RMS Media Types
RDX capacities range from 160 GB to 1.5 TB. RDX media displays with media type *UNKNOWN in IBM i version 7.1 and media type *RDX in subsequent IBM i versions.
Flash drives have a wide range of capacities, but drives larger than 32 GB are not supported by IBM i. IBM i allows the use of any flash drive that complies with the Universal Serial Bus Mass Storage Class and is USB 2.0. Flash drives display with media type *UNKNOWN in IBM i version 7.1 and media type *DEVICE in subsequent IBM i versions.
RMS Media Formats and Interchange
RMS media is formatted by the IBM i operating system with industry standard Universal Disk Format (UDF) version 2.5. Media that are recorded with UDF version 2.0 and 2.01 are also accessible for read or write. Media that are recorded with prior UDF versions are accessible as read-only.
Removing USB Storage Devices
Devices with an eject button, DVD, RDX, and tape drives, ensure that the media is properly quiesced and all the data is stored on the media before the device is ejected. Flash drives need an operation that is performed to ensure that the data is written to the media to allow the device to be safely removed. On IBM i use VRYCFG STATUS(*OFF), or use RMVOPTCTG or option 4 on WRKOPTVOL to eject the media. If the media is logically ejected, most flash drives report the drive is empty until the drive is unplugged and then plugged back in.
