IBM i added support for a new type of removable media late in 2012. Removable spinning disk (RDX) has become reliable and relatively fast, and can be used as a cost competitive save restore device. Prior to this support, removable media was either Tape or Optical. IBM called this new type of device Removable Mass Storage (RMS).
You can find the latest information on RDX device support on the Technology Updates page at IBM i IO Support Details.
RDX cartridges are very reliable, they are ruggedized to withstand a drop from up to 0.9 meters (36 in.) without damage, and they never need cleaning. A cartridge can be placed in either a USB or SATA dock to access the data.
Performance is better than typical for low cost tape drives (DAT), and the SATA device can achieve rates over 180GB/Hr. Chapter 9.29, RDX Device Performance, in the August 2013 Performance Capabilities Reference has the details (this is the final update of the PCRM and the only version still available).
Save/restore operations are done just as with a DVD, for example SAVLIB DEV(RMS01). Because it is an optical class device, you can also use IFS to manage data, e.g. WRKLNK OBJ(‘/QOPT/RDXVOL’). Commands are the normal optical storage commands (WRKOPTVOL, INZOPT, etc.). The IBM i Knowledge Center has a section on Removable Mass Storage (RMS).
Rather than create all new commands, we recognize that the media is random-access and spins, with fixed size physical blocks. That is similar to optical devices, so RMS devices are “optical class” devices to IBM i. RDX Docks are available as CEC installed SATA devices on 6.1.1, or as SATA or USB devices on 7.1 with Technology Refresh 5. Cartridges may be from 320GB to 1TB. Hardware details are available.
IBM i 6.1.1 support reports the dock as a 632A (generic DVD) when directly attached, and as a 632C (virtualized DVD) when a client.
IBM i 7.1 Technology Refresh 5 will report the device as a 63B8 regardless of native attached or virtualized client. This release may host the device, but only to another i partition.
There is no VIOS support for RDX drives.
The external USB devices allow the cable to be unplugged without a configuration change (removing the IOA from the partition, or powering off), but the device should be varied off (VRYCFG) before the device is unplugged.
The announcement material for new I/O features and the Technology Updates page on IBM i IO Support Details have additional information.
This week’s blog was written by Jim Tilbury who is the lead of the IBM i removable media team. Thanks, Jim!
This blog was edited to fix broken links on February 27, 2020.
This blog post was originally published on IBMSystemsMag.com and is reproduced here by permission of IBM Systems Media.