> For the complete documentation index, see [llms.txt](https://docs.nodeum.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.nodeum.io/data-archiving/hybrid-storage-management/tape-library-management/configuring-multipath-failover.md).

# Configuring Multipath Failover

This procedure is optional, but for libraries supporting Multipathing Failover feature, it is important to properly configure the libraries in NODEUM.

### Prerequisites

All components in the environment should meet the hardware vendor support standards for this feature. This includes the following:

* Fabric switches
* FC HBAs
* Tape library

OS driver levels and firmware levels of FC HBAs, and library and drives should be of supported revisions.

### lin\_tape driver

To use the lin\_tape device driver software, you need to install the driver. NODEUM has been tested with the latest available `lin_tape` driver, `3.0.72`, which can be downloaded and installed from the IBM fix\_central website.

Once you have followed the installation instruction provided by the vendor, you can verify that the driver is well installed:

```bash
$ lsmod |grep -i -E 'st|lin_tape'
lin_tape              483328  4
pfo                  1130496  1 lin_tape
st                     65536  0
```

You can see mediumx and tape drive devices:

```bash
$ lsscsi -g | grep -i -E 'medium|tape'
[11:0:0:0]   tape    IBM      ULT3580-HH5      F991  -          /dev/sg3
[11:0:0:1]   mediumx IBM      3573-TL          E.20  -          /dev/sg4
[11:0:1:0]   mediumx ADIC     Scalar i500      100A  -          /dev/sg5
[11:0:2:0]   tape    IBM      ULT3580-HH6      G9P1  -          /dev/sg6

$ cat /proc/scsi/IBMchanger
lin_tape version: 3.0.72
lin_tape major number: 237
Attached Changer Devices:
Number  model       SN                       HBA                       SCSI            FO Path
0       3573-TL     00L2U78AW009_LL0         qla2xxx                   11:0:0:1        NA
1       Scalar i500 VL001AV1506BVV00078      qla2xxx                   11:0:1:0        NA

$ cat /proc/scsi/IBMtape
lin_tape version: 3.0.72
lin_tape major number: 237
Attached Tape Devices:
Number  model       SN                       HBA                       SCSI            FO Path
0       ULT3580-HH5 90WT013124               qla2xxx                   11:0:0:0        NA
1       ULT3580-HH6 90WT054335               qla2xxx                   11:0:2:0        NA
```

### NODEUM Tape Library configuration

In following the standard Tape Library configuration, the tape library has to configured with the `lin_tape` library and drive emulation.

For doing this, you need to confirm that beside the defined tape library, the Emulation is set with the `lin_tape` emulation.

<figure><img src="https://1946775891-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FgzbGsZqZH8Ro8zxRYgwn%2Fuploads%2FPchFTxcBOfdkmrENTNv7%2Fimage.png?alt=media&amp;token=f9a6a73e-b6b8-48ee-9d16-d8dec37364e0" alt=""><figcaption></figcaption></figure>

This is the same for the Tape Drive(s):

<figure><img src="https://1946775891-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FgzbGsZqZH8Ro8zxRYgwn%2Fuploads%2F7nQW8cXKoFKvuzYMWeID%2Fimage.png?alt=media&amp;token=de8c322e-fb3c-45bb-8fbe-9be22929eb26" alt=""><figcaption></figcaption></figure>


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation by asking a question.

Perform an HTTP GET request on the following URL with the `ask` and `goal` query parameters:

```
GET https://docs.nodeum.io/data-archiving/hybrid-storage-management/tape-library-management/configuring-multipath-failover.md?ask=<question>&goal=<user_goal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is what the user is ultimately trying to achieve, the reason they need the answer. Sharing it helps GitBook give you a better, more relevant answer. A goal is most helpful when it describes the outcome the user wants rather than restating the question. For example, with `ask=how do I create an API token`, a goal like `automate deployments from our CI pipeline` lets GitBook tailor the answer to that use case.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.