Which discs and which burner to choose
An archive disc is a backup that is kept apart from the computer and its drives. A drive failure, a virus that encrypts files or files deleted by accident will not harm it. Sigelith Backup records discs by itself, with the mechanism built into Windows. No other program is needed.
Types of discs
| Disc | Holds about | Notes |
|---|---|---|
| DVD-R, DVD+R | 4.7 GB | |
| DVD-R DL, DVD+R DL | 8.5 GB | two layers |
| BD-R 25 GB | 24 GB | Blu-ray |
| BD-R 50 GB | 48 GB | Blu-ray, two layers |
| BD-R XL 100 GB | 97 GB | BDXL burners and drives only |
A BD-R disc holds a little less than its name says: the burner keeps part of the space as a spare area. The program takes this into account when planning.
M-DISC
M-DISC discs are intended by their manufacturer for long-term data storage. They come as DVD, BD-R 25 GB, BD-R 50 GB and BD-R XL 100 GB, and hold as much as an ordinary disc of the same kind.
The manufacturer's statement (Verbatim): the expected lifetime of M-DISC discs is several hundred years. The manufacturer bases it on tests to the ISO/IEC 10995 standard that the company Millenniata carried out on M-DISC DVD discs (1,332 years on average). This is the manufacturer's statement, not a promise from Sigelith.
Makers of ordinary recordable discs usually do not state a lifetime measured in decades. Treat such discs as a backup for a few years and check them regularly.
What the burner needs
- M-DISC discs: they must be recorded in a burner with M-DISC support (the manufacturer says: “M-DISC Ready”). According to the manufacturer, an M-DISC BD-R disc can then be read by most BD-R drives.
- Disc capacity: the burner must also support the capacity of the disc. A burner that records 25 and 50 GB M-DISC discs cannot always record a 100 GB disc: that needs BDXL support.
- 100 GB discs (BDXL): only a BDXL drive can read them, also many years from now. For an archive meant to last decades this matters, because ordinary Blu-ray drives are far more common than BDXL drives.
- How to check the burner: look in its description for the “M-DISC” mark, and for 100 GB discs also “BDXL” or “BD-R XL”.
- A USB burner is perfectly fine.
In the recording wizard, the “Check the disc in the drive” button reads the type of the inserted disc and its free space. It writes nothing to the disc.
What to choose
- An archive for decades: M-DISC BD-R 25 GB or 50 GB.
- A backup for a few years: an ordinary BD-R or DVD disc.
- When the data does not fit on one disc: the program splits it into a set of several discs by itself (see “Recording a large backup on several discs”).
Whatever the type of disc
- Every two years the program reminds you to check each disc (see “Checking a disc”).
- Keep a disc upright in its case, in a dark, cool and dry place. Do not stick labels on it. Write only on the transparent ring near the centre of the disc, with a solvent-free marker.
- A disc outlives drives. Keep a working drive (for example a USB one), or move the archive to a newer medium before drives disappear from the shops.
- A disc does not replace your other backups. Also keep a backup on a drive and an off-site backup. This is the 3-2-1 rule: three copies, on two kinds of media, with one of them off-site.