IPFS – Inter-Planetary File System. This is a peer-to-peer file sharing network using content addressing (object storage) to give each file a unique ID in a global namespace which connects IPFS hosts. These hosts, nodes or user-operators each hold a part of the overall data. It is said to be an alternative to the world wide web’s HTTP and HTTPS protocols.

IO – Input/Output – the transfer of information between two connected devices. Input from storage is associated with reading data a whilst output to storage means writing data.

Blu-ray – optical disk format for storing videos, audio files and archive data. It uses a 120mm (4.7 inches) diameter platter and was released in 2006, replacing DVDs. They were used for distributing movies with some archival storage use cases.

The polycarbonate disk is 120m in diameter metres (4.7 in) and 1.2 millimetres (0.047 in) thick, like DVDs. Blu-ray disks are written and read using a  405nm blue laser, and can store up to 50 GB in dual-layer format; 25GB in single layer format.

Distribution of movies by Internet streaming has replaced physical distribution by Blu-ray and the earlier DBD format optical disks. Panasonic produced archival Blu-ray technology.

DVD – Digital Video Disk – optical disk for storing videos, audio files and archive data. It uses a 120mm (4.7 inches) diameter platter. It was invented in 1995 in Japan and can store more data than the preceding CD (Compact Disk) format;  up to 4.7 GB in standard format – single-layer and single-sided, 8.5 GB with a dual-layered, single-sided disk, and up to  17.08 GB in an extended double-sided, double-layer format.

DVD-R and DVD+R can have data written to them by a DVD recorder, becoming DVD-ROMs which are read-only disks.

DVDs are written and read using a 650nm red laser, which is focused to different depths in a dual-layer disk.

DVDs can spin at up to 3,2000 rpm, faster than CDs at 2,300rpm.

The Blu-ray optical disk format, released in 2006, replaced DVDs, as dual layer Blu-ray disks, with their 405nm blue laser, have a much higher capacity; up to 50 GB.

ILM – Information Lifecycle Management. This is the concept of data (information) having a lifecycle from its birth to its death or near death as the rate of access to apiece of information slows over time. Imagine an online order being made. The transaction data is used a lot when the transaction is first made, when it is primary data. It is referenced by a payment subsystem and also by a delivery subsystem. A product system might use it. Then the information becomes secondary and is used for reference in, for example, weekly sales analyses and then, monthly and, eventually, yearly, at which point it is nn a tertiary phase. After that it may be archived for use at longer intervals, or even deleted. That is its lifecycle from creation (birth) to deletion (death). A corresponding idea is that it should be stored on different storage media at the different periods in its life, to reflect the need for less urgent access, and his less expensive storage, as it ages. See the HSM (Hierarchical Storage Management) entry.

IDE – Integrated Drive Electronics. An interface standard used for connecting storage drives to early personal computer systems. It was subsequently renamed to ATA (Advanced Technology Attachment.) PATA (Parallel Advanced Technology Attachment) is another version of IDE. There is more information here.

IB – InfiniBand. See InfiniBand entry.

InfiniBand – A Mellanox-invented high-speed, channel-based, lossless networking technology used in high-performance computing scenarios. It has high throughput and low latency and is an alternative to Ethernet. With InfiniBand, data can be transferred directly to and from a storage device on a system to userspace on another system, without the overhead of a system call needing CPU processing. InfiniBand adapters handle the networking protocols. It is different with Ethernet where the host CPU has to process the networking protocols. InfiniBand data tranfers don’t require host CPU involvement.

While Ethernet uses a shared medium concept InfiniBand is based on a switched fabric network architecture. Each receiving and transmitting device has a dedicated path to any other such device. This prevents network collisions and helps create predictable performance.

InfiniBand standard are looked after by the InfiniBand Trade Association and it has overseen a steady set of speed increases, termed xDR for <letter> Data Rate, as a table indicates;

As of Oct 2023 the XDR standard is being finalised and GDR is a roadmap item.

IaaS – Infrastructure-as-a-service. A public cloud or co-location service in which IT infrastructure equipment; compute, storage, and networking, is supplied  on demand, on a pay-as-you-go basis. Each resource can be offered as an individual service. Users install their own software and applications on such infrastructure and no longer have the necessity of provisioning their own servers, storage arrays and network boxes. PaaS (Platform-as-a-Service) is an extension of this to add system software.

Hellabibyte – 1024 yobabytes. See Decimal and Binary Prefix entry.

Hellabyte – a thousand yottabytes. See Decimal and Binary Prefix entry.

Holographic storage – a now-abandoned storage technology from the early 2000 era in which a holographic drive would use a CD-size disc with data stored as holograms within the depths of a recording medium. The holograms store pages of data which co-exist in the same physical space and are read or written by altering the angle of the lasers. Developer InPhase went into Chapter 11 bankruptcy in 2011.