LTO + LTFS FAQ

System or boot volumes contain lots of small files, links, devices and caches which will not copy to LTFS tape or disk. In addition the backup cannot be restored as a bootable volume.
All your projects, documents and data should be stored on a separate disk volume. This can be backed up to LTFS along with project media.
Use Time Machine for your system backup.
This way if you have a problem with the computer or need to change computers it will be very easy to start working quickly as all your creative data will be stored separately.
Note that Time Machine backups have a special structure and they cannot be copied to tape.

LTO-9 drives support the use of both LTO-9 and LTO-8 tapes. LTO-8 drives support LTO-8 and LTO-7 tapes. So each drive generation reads and writes the current and previous generation tapes.
LTO-7, LTO-6 and LTO-5 drives will read two generations back. So an LTO-7 drive will read / write LTO-6 and read LTO-5.

LTFS creates a separate partition for indexes that uses around 5% of the tape. Also YoYotta reserves about 100GB to ensure the tape does not over fill.

LTO-9 tape stores up to 17.4 TB and are a lot faster at 250-300MB/s and 350-400MB/s for full height drives.
LTO-8 tape stores up to 11.3 TB and are a lot faster at 250-300MB/s.
LTO-7 tape stores up to 5.6 TB and are a lot faster at 250-300MB/s.
LTO-6 tape stores up to 2.3 TB and are a little faster at 160MB/s.
LTO-5 tape stores up to 1.25 TB and can be read or written at 140MB/s.

Type-M allows new LTO-7 tapes to store up to 9TB instead of 6TB.
Type-M can only be written (and read) using an LTO-8 drive

Before formatting YoYotta can initialise new LTO-7 tapes loaded into an LTO-8 standalone drive as Type-M. No need to purchase tapes pre initialised.
The tape barcode should have M8 as a suffix. Note that once initialised they cannot be used as normal LTO-7 tapes.
In a library ensure the tape has M8 barcode labels and also check that the library firmware supports Type_M. The library reads the barcode and initialises the tape automatically on loading into the drive.

We don’t recommend using Type-M for long term archive as the tapes are only readable in an LTO-8 drive. They will not be readable in LTO-7 or LTO-9 drives. It was a short term solution introduced because of previous supply issues with LTO-8 tapes.

For larger archives we suggest using LTO-8 tapes which have now dropped well below LTO-7 pricing per TB.

Using tape compression is recommended, internally the LTO drive will compress files that are uncompressed.
Enable compression when formatting in the LTFS panel. The compression is lossless and varies from 1:1 to 2.5:1.
Uncompressed files like ARRIRAW, Phantom CINE, DNG and DPX can see a 10 to 20% space saving and these files will transfer faster.
Virtually all other video files contain compressed codecs like ProRes or H.264 so there won't be any reduction in size, but it's no slower so we recommend leaving compression enabled when formatting all tapes.
Also note that there is no risk in using compression, as compressed data is written to tape in exactly the same way as uncompressed data and on board hardware does the compress/decompress.
The theoretical ratio 2.5:1 allows the LTO vendors to quote a crazy compressed figures like 45TB on LTO-9 tapes. This would only be achieved with text or other files that compress easily. We haven't found anyone with that amount of text files !!

The potential compression is unknown until after data has been written, so the drive will show uncompressed space.
Some studios may ask for tapes with compression turned off, so check the delivery spec before formatting.

LTO drives perform speed matching, so they can run the tape slower to work smoothly with slower source devices.
The minimum speed needed to keep the tape writing continuously is 102MB/s for LTO-7, 112MB/s for LTO-8 and 177MB/s for LTO-9.
With a mix of different file sizes it's good to have a source bandwidth of at least 50% faster than this to keep the job going.
Note that the actual read speed with real files will never match a speed test results, so treat them as a rough guide. This means that a 1Gb NAS or a single hard drive will not be fast enough as a source.
A 10Gb NAS may work well, however if the NAS is being used by others at the same time it's performance will drop. If the tape drive runs out of data then the tape will have to keep rewinding and start writing again. You will hear this backhitch or "shoe shining" behaviour if you listen to the drive. When this happens the average speed will drop drastically. This won't damage the tape, however it will increase drive head wear.
So with slower sources it will be best to use YoYotta to copy the archive data to a direct attached Thunderbolt RAID.
A RAID like the Symply SPARK will have enough bandwidth to be simultaneously ingesting from a slower source and also running a tape archive.
Also with tape compression enabled, then the source read speed will need to be a little higher with uncompressed files like ARRIRAW and DPX.
In this case use YoYotta to create two sequential jobs. The first copy will be from NAS to fast RAID, then when complete YoYotta will index the new source folder and start a copy from the same RAID to tape. Another copy can now be started to the RAID to prepare for the next job. This process is described here.

For any data workflow, to ensure portability and acceptance by all applications and studios only use the following characters. This means no spaces. To enforce this turn on Strict file and folder naming in Preferences

• Alphabetic Characters [A-Z, a-z]
• Numeric Characters [0-9]
• Underscore [_]
• Hyphen [-]
• Full stop [.]

When this option is turned off then virtually all characters can be used.
Note that on the Mac the : (colon) character cannot be used. Also it's not recommended to use the / as it is not supported by Linux and Windows. If used it will appear as a colon.
As LTFS tapes are an archive and can be used cross platform it is best to avoid all the characters shown in the list below.

• macOS :
• Linux /
• Windows \ / : * ? " <> |

macOS and Windows file names can be up to 255 unicode characters in length including the file extension.
However Linux and LTFS support a shorter maximum of 255 8-bit characters. Unicode characters can be made of multiple 8-bit characters, so some files with valid names on macOS cannot be written to NAS, Linux file systems or LTFS tapes. YoYotta will warn about this.
So keep file names less than 250 characters and path names less than 1024 characters.
After indexing open the Source Browser and files with issues will have a red status. Edit the file names or zip the files, then reindex the job.

TAR is an older method of storing files as a bundle on a tape. There is no directory and the tapes cannot be mounted on the desktop. This makes it harder to retrieve individual files. YoYotta with LTO tape option supports reading of most TAR tapes, this allows easy migration to LTFS. Note that TAR restore is only supported by YoYotta when running on an Intel Mac. More information about restoring TAR tapes.

LTFS is an open standard file system, the current format version since 2017 is 2.4. Before that the format version was 2.2, these tapes can still be read. Tapes written can be read by LTFS running on Linux, macOS or Windows. So it's a cross platform archive. Older LTFS versions can still be read back. Tapes are formatted with a 6 character label, that matches the barcode label.
After formatting this label cannot be changed. To rename you will have to restore, reformat and copy the data again. LTFS stores the tape label in multiple indexes and also inside the tape chip memory.
Do not use / * ? <> " | \ : characters as these are not supported when the LTFS tape is mounted on a Windows system.
Keep file names less than 250 characters and path names less than 1024 characters.
LTFS does not support the use of WORM tapes.

LTFS tapes must be formatted with a unique 6 character code. The code can have the letters A-Z and numbers 0-9 in any order, for example 123456, ABCDEF, YO1234, 17376A. The tape barcode label is 8 characters, which is the user selectable 6 characters with either L5, L6, L7, M8, L8 or L9 on the end for LTO-5, LTO-6, LTO-7, LTO-M8, LTO-8 or LTO-9 tapes. For example 123456L5, ABCDEFL6, YO1234L6, 17376AL7. The six characters from the label must be used for the six digits when formatting.
Do not add any checksum or check digit.
It's best to use barcode labels for all tapes, this means that they can be used with an LTO library. Also barcode labels are an easy way to identify tapes.
Do not use the same 6 characters for copies of tapes
Do not use CLN as the first three characters as this prefix is reserved for cleaning tapes

Always make two copies of all material. One Main and one Safety (or clone) tape.
YoYotta will decode the barcode and show Main or Safety when selecting destination tapes, this can be ignored if you are not using one of the conventions below.

There are three suggested conventions for labelling main / safety tapes.

Odd/Even numbering YT0111, 127633, XTM127 are main tapes and YT0112, 127634, XTM128 are the matching safety tapes.
A-M / N-Z as the 5th letter HRSMDA, HRSMDB and HRSMDC are main tapes, HRSMQA, HRSMQB and HRSMQC are the matching safety tapes. This method allows 4 letter project codes (in this case HRSM) and 13x26 main and 13x26 safety tapes.
A/B as last character ABC12A, YY100A, H2122A, SHOW1A and 12567A are main tapes, ABC12B, YY100B, H2122B, SHOW1B and 12567B are the matching safety tapes.

After formatting you cannot change this label, as it is written into each index on the tape and also written to the chip inside the tape. To change the label you have to reformat the tape.

In Europe we can supply LTO tapes at great prices with custom YoYotta labels printed on durable plastic. They have a standard barcode, plus you can add unique text labels on the left as shown opposite. So you can clearly label Main and Safety, or add a project ident. Unlike other labels each tape can have a different code, you are not limited to a set sequence.
IBM make all LTO-7 and LTO-8 mechanisms, so we supply IBM Barium Ferrite tapes for perfect compatibility.
Contact support@yoyotta.com for a quote.

Keep your working tapes in the same room as the drive or library. If this is not possible then ensure they are in the room for 24 hours before use. This will allow the temperature of the tape to match the temperature of the drive.
The room temperature should be between 16 to 32°C with 20 to 80% humidity. This is a wide range, however it is important to keep this stable. Rapid changes in temperature or humidity are not good for electronic equipment.
Keep tapes in their cases and ensure that they are protected during shipping.

Tapes can be re-written hundreds of times, so for typical archive workflow there should not be any issues.
The LTO drive monitors tape read and write errors. The error count is stored in a memory chip inside the tape cartridge. When the tape is loaded YoYotta reads the error count. The error count cannot be reset so the history of previous errors is never lost.

Recovered errors
When writing sometimes retries are needed and the drive rewrites the data further down the tape. This reduces the capacity of the tape very slightly. These are logged as recovered write errors. Low recovered write errors are no problem even with a new tape, however large counts can indicate poor tape quality or a drive issue. Recovered read errors indicate that the drive needed to retry the read, again low counts are normal. But high rates in the hundreds or thousands indicate a problem with the tape or drive.

If a tape shows a high recovered error count mount it and note the error counts from the YoYotta popup log. Now run a full restore to a local RAID. The restore will automatically verify the tape so see if there are any issues. Afterwards remount and see if the count has increased. If there are verification issues or the count increases by a lot it will be best to make a new copy of the tape. If the tape restores OK and the counts are similar then it is likely that the tape has been used in another drive that has hardware issues.

Permanent errors
These errors are logged when a read or write to tape fails. The read or write job will appear to have hang however the drive will keep retrying for 20 minutes so just leave it to finish.
They will also occur if the drive is disconnected or powered off whilst a tape is loaded. Each error may cause a file to be unreadable, however it is possible that the file has been rewritten so the affected area of the tape will no longer be used. Permanent errors can also be caused by a drive or interface hardware issue or damage to a tape. For example if a tape is dropped the edge can be damaged causing some parts of the tape to become unreadable.
To check the tape it's best to run a full verification. See Verifying LTFS Tapes

As long as you have at least two verified copies stored in different locations and look after the tapes then the chance of data loss is extremely minimal. Much less chance than storing data on other mediums like SSD or HDD. We suggest that you do not continue to use a tape with multiple permanent erors or hundreds of temporary errors. If you have another tape with this data, replace the original with a copy. If this is the only copy then restore the data and create another copy.
If you create another tape and it also has problems, then there may be an issue with the drive.

If there are errors restoring a file then YoYotta will log the file that cannot be read in the popup log. Locate the safety copy of this tape, open the Source Browser, then setup a selective restore job just for that file. If you don't have another copy then instead setup a selective copy just for the file that is having issues and turn on Recovery Read in the LTFS setup panel. YoYotta will attempt to read the file in small parts, so it will take a very long time. That is why you only want to use this mode to recover a few files and turn if off afterwards.

There is no technical requirement to reverify tapes that are in storage. Whenever you restore from tape YoYotta will reverify the files. You can also run a full verification at any time.
See Verifying LTFS Tapes

Reformatting the tape does not clear these errors and is not a solution for a bad tape. If a tape was written and verified without error and then later on when reading back errors occur this indicates that the tape may have been damaged or the drive is faulty. Monitor the error counts when mounting tapes, if multiple tapes are affected then it's likely that the LTO drive needs servicing.

After about 4 years of daily use, LTO drive heads can wear causing the drive to skip over tape, files are written OK, but the tape capacity is reduced.

When mounted by YoYotta the tape will also appear in the Finder (Finder, Go, Computer). The tape icon will appear on the desktop if Connected Servers is turned on in Finder Preferences.
You can browse the tape and this will be quick as long as there are only folders on display. When navigating into folders with files then this will get very slow as the Finder tries to create thumbnails and metadata. It is possible to drag and drop folders and files on the tape using the Finder, but there is no verification and also the file creation and modified times will be not be preserved.

If the Mac sleeps after a Finder or Terminal transfer then the files written to tape may be lost.
There are also other technical reasons, so using the Finder is not recommended or supported.
YoYotta should not be used to mount tapes for any external transfers.

Whilst LTFS tapes are mounted if using other apps that require use of the macOS File Open panel to select non tape files, then you may find that that you see the busy cursor.
Turn on Disable Finder browsing in the LTFS panel, then the tape will not show up in any Finder windows. This can speed up non tape access for other apps including the Finder.

If you need to access a tape without using YoYotta then you can type the following into a terminal window.
The terminal app is located in /Applications/Utilities
ltfs -o devname=0 /Volumes/LTFS1
The tape will appear in the Finder. There is also an eject button in the Finder.

Files can be moved using the Finder. Files and folders can be renamed. Folders cannot be moved on tape.
However moving or renaming this will mean that the reports and indexes will no longer be correct for the tape.
Immediately after making any changes unmount the tape.
So after making the changes store a new index using the Source Browser. See Indexing Tapes
Then afterwards export new reports from the Project Browser.

If files or folders are deleted from tape using the Finder or command line they will be removed from the tape directory. Note that the space is not recovered, so for this reason there is no delete function in YoYotta. If a large number of files need to be removed, then it is best to reformat the tape and start again. Files can be moved on tape, but folders cannot. So it is best to organise the structure on the source drive and also setup the destination paths before starting the job. It is also possible to create an empty folder on the source and link files and folders into it. Then turn on Copy linked files and folders in the Preferences panel. Immediately after making any changes unmount the tape.

YoYotta does not encourage copying from one tape drive directly to another tape drive. Here are some reasons why this is discouraged.

If the tapes or drives are mismatched in generation or age then the tape read speed may not match the tape write speed. This can lead to data over or under run, a drive will try to match write speeds but there are limits to this.

When YoYotta indexes the source tape it won’t extract full metadata unless the tape was written by another YoYotta system. (because this would involve reading back each clip which takes a very long time from tape)

If the tape has been written out of order (which is quite common when written with 3rd party software) then YoYotta will have no choice but to replicate the same order.

Here is a suggested duplication workflow.
First restore the tape to a local RAID. Add the restored folder as a new job, YoYotta will index and create full metadata, then a copy can be made in a clean efficient order. If you are just copying one tape then it will take a bit longer, but the benefits outweigh the extra time. If copying multiple tapes then after restoring the first tape you can overlap the archive and the next restore by running simultaneous jobs. Then there is no time penalty.

However if you have tested the workflow then you can still add a tape as a destination and copy directly from one to the other.
Mount the tape manually using the controls in the LTFS panel, then click Choose Other, add the tape as a destination and run the job.

The read/write heads on an LTO drive need to cleaned periodically. Loading a cleaning tape into the drive starts an automatic cleaning process that takes a few minutes. So make sure you have a cleaning tape, as once the drive says CLEAN NOW it must be cleaned. The cleaning tape can be used about 50 times. Before and after cleaning YoYotta will show the remaining clean count.
When cleaning is needed a standalone drive will shown a C on the front panel display. A tape library will show a warning on the front panel. For both drive types CLEAN SOON and then later on CLEAN NOW will appear in the LTFS panel.
Avoid cleaning until the CLEAN SOON warning appears.
If the drive ejects the cleaning tape and shows error code 7 then the cleaning tape has expired and needs to be replaced.
When CLEAN SOON appears there will be a few days before CLEAN NOW appears.
When CLEAN SOON appears, if there are queued jobs in the table after the current job, then click the start button for each one to dequeue them. Then when the current job completes run the clean. After cleaning is finished, click the start button for each job to resume the queue.

Desktop drive
Load the cleaning tape and cleaning will start automatically.

LTO library drive
Load a cleaning tape with a CLN barcode label. If the tape library has multiple drives turn off the enables in the LTFS panel for the other drives.
Then select the cleaning tape in the LTFS panel and click MOUNT to load and clean the drive. When complete eject the tape and re-enable all drives.
In the LTFS panel you will see the number of cleans remaining for the cleaning tape.

Cleaning tape barcode label
The IBM spec states that the cleaning tape barcode label starts with CLN followed by one alphanumeric character and two numbers. With L1 as the tape type.
The important thing is to make sure the barcode label starts with CLN.
Examples are CLN001L1, CLN002L1, CLN003L1, CLNU01L1.

YoYotta does not automatically mount tapes unless a job is running. It is is best to wait until the tape is needed before mounting.
If you want to see what's on a tape see Indexing LTFS tapes.
Some other apps have this auto mount "feature". If a tape mounts automatically, (it may appear mounted with ltfs in the name) then you must disable this. Tapes mounted by other apps may not be recognised by YoYotta.
Retrospect can be disabled in System Preferences.
Codex has an Auto Mount Tapes switch in their preferences. Turn this off.

When all YoYotta jobs complete, all tapes will be unmounted, this ensures that the tape indexes are updated and helps protect their contents.