Sharing Tape Libraries Across Partitions Without VIOS
May 4, 2020 Alex Woodie
IBM i shops have a love-hate relationship when it comes to the Virtual I/O Server, or VIOS. With the latest IBM i Technology Refresh, IBM is giving the anti-VIOS group a feature they have been requesting: the capability to easily share a tape library among multiple logical partitions, or LPARs without involving VIOS, SANs, or multiple adapters.
IBM is calling the new feature “IBM i Virtualization for Tape Libraries,” and it’s based on RFE (request for enhancement) number 127631. While the words “tape libraries” and “virtualization” are in there, this is not a virtual tape library (VTL) solution. That already exists on IBM i and it’s something else. Rather, this new thing is about virtualizing the access from IBM i environments to real tape libraries.
The new feature is similar to the client virtual tape device support that has allowed IBM i shops to share individual tape drives and optical devices with multiple logical partitions (LPARs) since version 6.1. But the new feature expands the client virtual device support to certain IBM tape libraries.
IBM i Virtualization for Tape Libraries support is available on IBM i versions 7.4, 7.3, and 7.2, provided they have the right PTFs (see below). The feature is supported with any combination of those IBM i versions, on either the server or client partitions.
According to IBM, it’s now just as easy to share a tape library as it is to share a stand-alone tape drive. With the change made to the network server description (NWSD) on the target LPAR, customers can now connect IBM tape libraries via SAS and Fibre Channel connections, or via a SAN connected with a single adapter.
Only a select group of entry and midrange IBM tape libraries support the new feature. The models supported include IBM TS2900 (3572), IBM TS3100/3200 (3573), and IBM TS4300 (3555).
The big benefit of this enhancement is that customers no longer have to use manual operations to share a tape library among IBM i partitions. That means no more varying off the library, disconnecting the LPAR, and then varying the device back on to a new LPAR, IBM says.
IBM i Chief Architect Steve Will says the new feature will benefit IBM i shops, particularly those that don’t use VIOS.
“Our clients use tape libraries, a lot, and they want to be able to share those,” Will told IT Jungle recently. “In this new environment, where so much is virtualized, so many of our clients didn’t like having to use VIOS, didn’t like the complexities of removing a tape library from one partition and adding it to another. That really wasn’t sharing. It was just a way of de-allocating or re-allocating.”
With the new IBM i Virtualization for Tape Libraries feature, those libraries can now be shared very easily, Will says.
“There’s no VIOS involved, which [benefits] for our low-end clients who don’t have skills in that UNIX management space, which essentially is what the VIOS is,” he says. “They can use tools to easily share a virtual tape library across partitions. For our smallest clients who only have one partition, that’s not a big deal. But for a lot of our clients in the larger small and medium range, they’re using tape libraries and they want to be able to share that.”
IBM received a specific enhancement that requested IBM i to function like NPIV, or N-Port ID Virtualization, which is a technology available on IBM storage area networks (SANs). Essentially, the RFE called for a simple hosting environment without VIOS to get NPIV-like behavior, IBM says.
“We couldn’t do it actors every storage device,” Will says. “But we are happy to finally be able to give them a little more ease-of-use in this space.”
The new feature requires several PTFs. For IBM i 7.4, the feature is enabled with PTF MF66863, and other requisite PTFs include MF66860, MF66861, MF66862, MF66837, MF66825, and MF66840. For IBM i 7.3, the feature is enabled with MF64802 and other requisite PTFs include MF66857, MF66858, MF66859, MF66836, MF66824, MF66839, and SI70255. For IBM i 7.2 the feature is enabled with MF64803 and other requisite PTFs include MF66854, MF66855, MF66856, MF66835, MF66823, MF66838, and SI70254.
For more information, see the Client Virtual Tape Devices section of the IBM i support website. You can also find more information in the Client Virtual Tape Devices section of the IBM Knowledge Center.