"In library and archival science, digital preservation is a formal endeavor to ensure that digital information of continuing value remains accessible and usable. It involves planning, resource allocation, and application of preservation methods and technologies, and it combines policies, strategies and actions to ensure access to reformatted and "born-digital" content, regardless of the challenges of media failure and technological change. The goal of digital preservation is the accurate rendering of authenticated content over time. The Association for Library Collections and Technical Services Preservation and Reformatting Section of the American Library Association, defined digital preservation as combination of "policies, strategies and actions that ensure access to digital content over time." According to the Harrod's Librarian Glossary, digital preservation is the method of keeping digital material alive so that they remain usable as technological advances render original hardware and software specification obsolete. The need for digital preservation mainly arises because of the relatively short lifespan of digital media. Widely used hard drives can become unusable in a few years due to a variety of reasons such as damaged spindle motors, and flash memory (found on SSDs, phones, USB flash drives, and in memory cards such as SD, microSD, and CompactFlash cards) can start to lose data around a year after its last use, depending on its storage temperature and how much data has been written to it during its lifetime. Currently, 5D optical data storage has the potential to store digital data for thousands of years. Archival disc-based media is available, but it is only designed to last for 50 years and it is a proprietary format, sold by just two Japanese companies, Sony and Panasonic. M-DISC is a DVD-based format that claims to retain data for 1,000 years, but writing to it requires special optical disc drives and reading the data it contains requires increasingly uncommon optical disc drives, in addition the company behind the format went bankrupt. Data stored on LTO tapes require periodic migration, as older tapes cannot be read by newer LTO tape drives. RAID arrays could be used to protect against failure of single hard drives, although care needs to be taken to not mix the drives of one array with those of another. [...] "
... zobacz więcej