For organizations with large volumes of digital content, keeping every byte on expensive SSDs is financially unsustainable. A tiered storage approach balances accessibility with cost.

Modern data management structures often categorize information into three distinct tiers based on performance requirements and access frequency:

T1 (Tier 1 – Hot Storage): Houses active, mission-critical data demanding immediate access. It utilizes high-speed NVMe and solid-state drives (SSDs) to achieve the lowest latency possible.

T2 (Tier 2 – Warm Storage): Contains data that is accessed regularly but does not require the highest performance. This tier typically utilizes high-capacity Hard Disk Drives (HDDs) to balance performance and budget.

T3 (Tier 3 – Cold / Archive Storage): Reserved for data that is accessed infrequently. This tier has the lowest performance requirements but demands the highest capacity, lowest cost per terabyte, and maximum long-term retention safety. Common media types are low-cost, high-capacity magnetic tape libraries and deep cloud archival storage services including AWS Glacier and Azure Archive Tier storage.

XenData LTO archive systems include a managed disk volume which acts as a cache, and this can also be used as T2 storage for content that needs faster access than available from T3.  As data on T2 goes untouched for a defined retention period (e.g., 30 days), the XenData HSM software purges it from the disk cache and makes it accessible from LTO tape. The file system leaves behind a tiny pointer file (stub). When an application reads the stub file, the HSM automatically instructs the robotic arm to grab the specific LTO cartridge, insert it into a tape drive, and stream the data back to the application.

Several key advantages make LTO (Linear Tape Open) data tape the optimal choice for on-premises T3 archival storage:

1. Unrivaled Cost-Effectiveness – When calculating the Total Cost of Ownership (TCO) for large-scale data retention, tape significantly beats out hard drives and cloud alternatives. Magnetic tape media provides a drastically lower price per terabyte compared to spinning disks. Additionally, hard drive arrays must spin constantly, generating high electricity and cooling bills. In contrast, an idle LTO tape sits silently on a shelf or inside a robotic library slot consuming zero power.

2. Unmatched Reliability and Durability – Hard drives are vulnerable to mechanical failures, head crashes, and magnetic degradation, usually lasting about 5 to 8 years in normal use. LTO tape cartridges are rated for a life of 30+ years under stable environmental conditions.

3. The Ultimate Ransomware Defense: The Air Gap – In today's cybersecurity landscape, the physical nature of tape storage provides an unmatched security layer. Once an LTO tape is ejected from a tape drive, it creates a literal "air gap"—a physical separation between the data and any network connection. Because the data is offline, malicious actors cannot encrypt or delete it via malware or ransomware attacks. Furthermore, when a file is overwritten, the prior versions are retained on tape, allowing for recovery without paying a ransom.

In summary, by reserving Tier 1 and Tier 2 resources for frequently accessed data and offloading other content to LTO tape libraries, organizations can drastically cut power consumption and hardware costs. As a highly secure, long-lasting, and exceptionally economical medium, LTO tape remains the undisputed backbone of enterprise Tier 3 deep archives.

Traditionally, file systems and object storage were considered incompatible because they operate on different architectural principles. However, with modern architectures— as used by Amazon S3 Files and XenData X-Series LTO and E-Series disk appliances —they can now coexist seamlessly, allowing applications to simultaneously read and write to data storage as an S3 bucket and network file system.

A file system uses a tree structure of directories, sub-directories, and files. When files are written to object storage, every file is an object that is stored flatly. However, it has become very common for "directories" to be created on object storage by adding the full file path to the name using slashes (/) to specify the directory structure.

Coexistence can yield big operational benefits. Organizations can run file-based applications and S3 workflows using the same storage repository. Even if only a file system interface is needed today, this coexistence positions organizations to add S3-based applications in the future.

Linear Tape File System (LTFS) is an interchange format for writing to Linear Tape Open (LTO) magnetic tape cartridges. Introduced with LTO-5 in 2010, LTFS is the dominant format for interchange between different systems. It lets you mount an LTO tape directly onto Windows, macOS, or Linux, giving you a standard directory tree structure.

All XenData LTO systems offer LTFS as a format for writing to LTO-5 and later generation cartridges. Furthermore, they allow LTFS cartridges written by other systems to be easily imported into the XenData system.

LTO compatibility applies equally to rewritable and WORM cartridges and is summarized below for LTO drive generations from LTO-5 to LTO-10.

Native capacities of LTO cartridges are shown below. These are the capacities without any compression.

Note (*): 1 TB equals 10¹² bytes

Universal LTO cleaning cartridges break the compatibility matrix rules. A single universal cleaning cartridge is designed with a specialized cleaning material that is structurally compatible across all LTO drive generations.