Archival data storage requirements are growing at over 60% annually. The LTFS format is an  ideal option for long-term archiving of large files that must be easily shared with others. This  option is especially important because the tape media that it uses (LTO and 3592) are  designed to have a 15 - 30 year lifespan (depending on the number of read/write passes). Industries that most benefit from this tape file system are the banking, digital media, medical,  geophysical, and entertainment industries. Many users in these industries use Linux or  Macintosh systems, which are fully compatible with LTFS. LTO Ultrium tape cartridges from earlier LTO generations (that is, LTO-1 through LTO-4)  cannot  be partitioned and be used by LTFS/IBM Spectrum Archive. Also, if LTO Ultrium 4 tape  cartridges are used in an LTO Ultrium 5 tape drive to write data, the LTO-4 tape cartridge is  treated as an unpartitioned LTO-5 tape cartridge. Even if an application can manage  partitions, it is not possible to partition the LTO-4 media that is mounted in an LTO Ultrium 5  drive.  Starting with the release of IBM Spectrum Archive EE V1R2, corresponding Write Once,  Read Many (WORM) tape cartridges are supported in an IBM Spectrum Archive EE solution  operating supported IBM Enterprise tape drives. With the same release, tape drives in mixed  configurations are supported. For more information, see 7.23, “Tape drive intermix support”  on page 204. Although LTFS presents the tape cartridge as a disk drive, the underlying hardware is still a  tape cartridge and is therefore sequential in nature. Tape does not allow random access. Data  is always appended to the tape, and there is no overwriting of files. File deletions do not erase  the data from tape, but instead erase the pointers to the data. So, although with LTFS you can  simultaneously copy two (or more) files to an LTFS tape cartridge, you get better performance  if you copy files sequentially. To operate the tape file system, the following components are needed: Together, these components can manage a file system on the tape media as though it is a  disk file system for accessing tape files, including the tape directory tree structures. The  metadata of each tape cartridge, after it is mounted, is cached in server memory. Therefore,  metadata operations, such as browsing the directory or searching for a file name, do not  require any tape movement and are quick.  GLYPH<SM590000> Software in the form of an open source LTFS package GLYPH<SM590000> Data structures that are created by LTFS on tape Chapter 2. IBM Spectrum Archive overview  17