Every cartridge in a tape library needs a way to be identified without being loaded into a drive. That is the job of LTO barcode labels: a small adhesive strip read by the library, so it and your backup or archive software, know exactly which tape it is and which LTO generation it belongs to. Get the label right and inventories take seconds. Get it wrong and the library may reject the cartridge or mix up your tapes.
This guide explains the LTO barcode label format, the media ID codes for every current generation from LTO-5 to LTO-10, and how to apply and number your labels correctly.
What is an LTO barcode label?
An LTO barcode label combines two things: a barcode that a tape library can scan, and the same characters printed in human-readable form underneath. Together they form the cartridge’s volume serial number, usually known as the VOLSER.
When a tape library or autoloader starts up, its barcode reader scans every slot and builds an inventory from these labels. Backup and archive applications then use the same VOLSER as the tape’s reference in their catalogue, so they can ask the library for a specific cartridge and know exactly what is stored on it.
Standalone desktop and rackmount LTO drives do not read barcodes, so the label is not required there. Many users still label every tape, because a clear, unique VOLSER makes shelves of cartridges far easier to manage.
LTO barcode label format
Standard LTO barcode labels follow the same structure across all generations:
- 8 characters in total: uppercase letters A–Z and numbers 0–9
- Characters 1–6: the volume serial (VOLSER), which identifies the individual cartridge, for example SY3525
- Characters 7–8: the media ID, which identifies the LTO generation and type, for example L9 for an LTO-9 data cartridge
- Code 39 (USS-39) barcode, the symbology LTO libraries are designed to read
A complete label reads SY3525L9: cartridge SY3525, LTO-9 data tape.
LTO media ID codes by generation
The last two characters must match the cartridge the label is stuck on. LTO-10 introduced new codes, including a separate code for the 40 TB cartridge.
| LTO generation | Data cartridge | WORM cartridge |
|---|---|---|
| LTO-5 | L5 | LV |
| LTO-6 | L6 | LW |
| LTO-7 | L7 | LX |
| LTO-8 | L8 | LY |
| LTO-9 | L9 | LZ |
| LTO-10 (30 TB) | LA | LH |
| LTO-10 (40 TB) | PA | – |
Cleaning cartridges use their own format: the label starts with CLN, followed by a three-character sequence, and ends with CU for a universal cleaning cartridge, for example CLN001CU. This tells the library to treat the cartridge as a cleaner rather than a data tape.
Do you need barcode labels?
If you use a tape library or autoloader, yes. The library relies on barcodes to inventory its slots, and most backup and archive software expects every cartridge to have a valid, unique label. Our SymplyPRO XTL tape libraries are a typical example: the barcode reader identifies each cartridge as the library scans its slots.
With a single desktop or rackmount drive, labels are optional, but still recommended. A consistent labelling scheme makes it easy to match a cartridge on the shelf to the entry in your archive catalogue, and it saves time if you move to a library later.
How to apply LTO barcode labels correctly
Most barcode read errors come from how the label is applied rather than the label itself. Follow these rules:
- Use the recessed label area only. A label that overlaps the edge of the cartridge can cause loading problems in the drive or library.
- Apply it straight and flat, with no bubbles or lifted corners.
- Never stick a new label on top of an old one. Remove the old label completely first.
- Use non-glossy labels. Glossy or reflective surfaces can stop the barcode reader from scanning reliably.
- Don’t write on or cover the barcode, including with tape or extra stickers.
- Match the media ID to the cartridge. An LTO-9 label on an LTO-10 cartridge will confuse the library and your software.
Pre-printed, custom or self-printed labels?
Pre-printed sequential labels
The simplest option. Labels come on sheets in a continuous sequence, for example SY0001L9 to SY0100L9, with the correct media ID already printed. They are made to the LTO specification, so they scan reliably.
Custom and colour-coded labels
Label suppliers can print your own VOLSER ranges, and many offer colour-coded characters, which make individual numbers easier to read at a glance on a shelf or in a library magazine. Custom ranges are useful if you want different prefixes for different projects, sites or departments. Symply’s own media uses this style: an SY prefix followed by colour-coded numbers, for example SY3525L9.
Printing your own labels
It is possible to print LTO barcodes yourself, but it is the most common source of read errors. The barcode must meet the Code 39 specification for bar width and print quality, the label stock must be non-glossy and the right size for the recessed area. For anything that goes into a library, pre-printed labels are always the safer choice.
Choosing a numbering scheme
Your VOLSER becomes the name of the tape in your software, so it is worth planning before you label your first cartridge:
- Keep every VOLSER unique. Two tapes with the same label in one library or catalogue will cause conflicts.
- Use prefixes with meaning, for example one range for primary archive copies and another for off-site or vault copies.
- Leave room to grow. Six characters give you plenty of combinations, so avoid schemes you will outgrow in a year.
- Keep the same VOLSER if a label is damaged. Replacing it with an identical label means your software still recognises the tape.
LTO barcode labels: quick FAQ
Can I use LTO-9 labels on LTO-10 tapes?
No. The media ID must match the cartridge. LTO-10 data cartridges use LA (30 TB) or PA (40 TB), while L9 identifies an LTO-9 cartridge. Using the wrong code can cause the library to misidentify or reject the tape.
Do desktop LTO drives need barcode labels?
No. Standalone drives don’t scan barcodes, but labels still help you organise and find tapes, especially as your archive grows.
Do LTO cartridges come with labels?
Some do, some don’t. Depending on the supplier, cartridges are sold unlabelled, with a set of labels, or pre-labelled. If you use a library, check that the labels supplied use the right media ID and a VOLSER range that doesn’t clash with tapes you already have.
What happens if a label can’t be read?
The library usually reports the slot as unreadable or unlabelled, and your software may not be able to select that cartridge. Replace the label with a new one using the same VOLSER, applied cleanly in the recessed area.
Get your LTO setup right
Labels are a small detail, but they keep a growing archive organised and libraries running smoothly. Whether you are labelling LTO media for a single drive or filling a library, Symply can help you choose the right hardware, from desktop and rackmount LTO-10 tape drives to the SymplyPRO XTL tape libraries.
Planning a move to a new generation? Read our LTO migration guide, or see our LTO tape FAQ for more answers about LTO tape.