HP Storage HP Linear Tape File System (LTFS) Linux and Mac User Guide Abstract This document provides information about the HP Linear Tape File System (LTFS), which presents an LTO-5 or LTO-6 SAS tape drive and media as a disk volume.
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Contents 1 Introduction...............................................................................................4 Features..................................................................................................................................4 Benefits...................................................................................................................................4 Intended usage.................................................................................................
1 Introduction This guide provides information about the HP Linear Tape File System (HP LTFS) Software. HP LTFS makes tape self-describing, file-based, and easy-to-use and provides users with the ability to use standard file operations on tape media for accessing, managing and sharing files with an interface that behaves as a hard disk. In addition, HP LTFS provides the ability to share data across platforms, as you would with a USB drive or memory stick. NOTE: A firmware update may be required.
and updating individual files) will not perform as well as streaming large files to and from tape. • The HP LTFS application will work in conjunction with graphical file explorer programs such as Nautilus or Konqueror (on Linux). However because these types of applications tend to try to pre-read files in the directory, using the graphical explorer window may lead to poor performance. For optimum performance, use a terminal window and issue shell commands to copy data, view directory contents, and so on.
2 Linux: Installation and configuration When using HP LTFS with LTO-5 or LTO-6 tape drives, the following components are required: • A drive firmware revision that supports dual partitioning. HP LTFS will check and tell you if your tape drive needs updating. HP L&TT should be used if a firmware update is required. • The software package that contains the “run-time” executable. This can be found at: http://www.hp.com/go/ltfs • The FUSE kernel module NOTE: HP L&TT can be downloaded from http://www.hp.
It will also place a number of dynamic libraries in /usr/local/lib/ and in a new subdirectory called /usr/local/lib/ltfs/ . 5. HP LTFS is now installed. See (page 10) for next steps. IMPORTANT: The precompiled binaries supplied by HP require additional shared libraries which may not be present on every system, or which may need to be updated in order for the binaries to execute. Refer to the LTFS release notes for more details.
3 Mac OS X: Installation and configuration When using HP LTFS with LTO-5 or LTO-6 tape drives, the following components are required: • A drive firmware revision that supports dual partitioning • The software package that contains the “run-time” executable • The OSXFUSE kernel module (or, for older systems, the MacFUSE kernel module) NOTE: HP LTFS will check and tell you if your tape drive needs updating. HP L&TT should be used if a firmware update is required. It can be downloaded from http://www.hp.
To uninstall LTFS If at a later date you want to uninstall HP LTFS from your system, delete /usr/local/bin/*ltfs* and then delete the tree under /Library/Frameworks/LTFS.framework. The GUI management application can be uninstalled by dragging it to the Trash. To cause the Package Manager subsystem to remove references to LTFS, execute the command: pkgutil --forget com.hp.ltfs To delete the ICU package as well, delete the tree under/Library/Frameworks/ ICU.framework.
4 Using HP LTFS How to use LTFS NOTE: On Mac OS X, you can execute steps 1–3 and 5 more easily using the HP StoreOpen Standalone application, installed by default in your Applications folder when HP LTFS is installed. This graphical user interface (GUI) application will guide you through the steps required to select a tape drive, load and format a tape cartridge, and then mount the cartridge into the file system.
$ ltfs /mnt/lto5 ltfs options: –o devname= Tape device (default:/dev/st0) –o work_directory= LTFS work directory (default:/tmp/ltfs/) –o trace Enable diagnostic output –o eject Eject the cartridge after unmount –o sync_type= Specify sync type (default:time@5). should be specified as follows: • time@min: LTFS attempts to write an index each min minutes; min should be a decimal number from 1 to 35791394.
Usage details Format version compatibility Earlier versions of the HP LTFS application supported the previous LTFS format specification; version 2.1.0 onwards supports the updated LTFS format specification. LTFS volumes created with application v2.1.0 or later will not be readable in older versions of the LTFS application, as shown in the following table: Table 1 LTFS compatibility LTFS application Cartridge written by LTFS application v1.1.0 or earlier Cartridge written by v2.1.0 or later v1.1.
Table 2 Index update options sync_type Index is flushed to tape Potential benefits Potential downsides unmount When a volume is unmounted • Minimal capacity overhead • Exposure to risk of power (default LTFS v1.1.0 behavior) fails during writing • No impact on performance time@n Every n minutes during writing • Exposure to risk of power (default LTFS behavior from fails is limited to the last n v1.2.
Limitations • When the tape cartridge is almost full, further write operations will be prevented. The free space on the tape (such as from the df command) will indicate that there is still some capacity available, but that is reserved for updating the index when the tape is unmounted. • Future mounts of a cartridge that is almost full (has passed the point at which “early warning” is reported) will mount as Read Only, to prevent further modifications which may not fit on tape.
5 HP TapeAssure drive monitoring A drive-monitoring service for HP LTFS on Linux and on Mac OS X is available as a separate download, offering access to: • Drive Health—write/read quality levels, key drive life indicators, and any service actions • Drive Performance—host and media transfer rates and compression ratios • Drive Utilization—the time the drive is in use, as a percentage • Tape Health—effective capacity, key tape life indicators and any service actions • Tape Utilization—write and read
6 Troubleshooting General If problems occur during HP LTFS operation, entries may be made in the system log (such as /var/log/messages on RHEL systems). Check for entries made with the service name “ltfs”. Both ltfs and mkltfs have command line options to report further details of the operations undertaken, which may help when trying to troubleshoot problems. If there is a problem with drive interaction, HP LTFS will attempt to create a snapshot of the drive’s internal state at the time of failure.
Using HP LTFS to check the cartridge Every time a cartridge is mounted onto the system, the HP LTFS application will perform a consistency check to ensure that the index information is accurate and up-to-date with the data on the tape. If for some reason there is a problem, the mount operation will fail. In order to recover the tape to a consistent state, you can use the ltfsck utility to check and repair the LTFS volume.
7 Frequently asked questions Q: How do I get HP LTFS? A: All application downloads and documentation are available from the website at:http:// www.hp.com/go/ltfs. Q: What are the minimum system requirements? A: Any server that fulfills the needs of the supported configurations detailed in Supported configurations (page 5). Q: Does HP LTFS support DDS/DAT devices? A: No. Only LTO-5 and LTO-6 drives are supported.
8 Support and other resources Contacting HP For worldwide technical support information, see the HP support website: http://www.hp.
Typographic conventions Table 3 Document conventions Convention Element Blue text: Table 3 (page 20) Cross-reference links and e-mail addresses Blue, underlined text: http://www.hp.
