Exabyte to Pebibyte

One exabyte = 1,000,000 terabytes = 1,000 petabytes. If you filled 1 TB external hard drives and stacked them end to end, 1 EB worth would stretch roughly 200 km. In content terms: 1 EB can store about 250,000 years of HD video, or about 100 billion hours of music at 128 kbps. All the data produced by the Large Hadron Collider per year is about 15 petabytes — still 67× less than one exabyte.

Global data creation, capture, copy, and consumption is estimated at roughly 2.5 exabytes per day (IDC 2023 estimate), growing roughly 23% annually. This includes IoT sensor readings, financial transactions, social media posts, surveillance camera footage, scientific instrument output, and all other digital activity. Most of this data is transient and never stored long-term.

Amazon Web Services, Microsoft Azure, and Google Cloud each store estimated tens to hundreds of exabytes of customer data in their cloud platforms. Meta (Facebook/Instagram) stores an estimated 100+ exabytes across all data types. The NSA's Utah Data Center is estimated to hold yottabytes in capability, though actual stored volumes are classified. Collectively, global cloud storage is in the hundreds-of-exabytes range.

An exabyte (EB) = 10¹⁸ bytes (SI decimal). An exbibyte (EiB) = 2⁶⁰ bytes = 1,152,921,504,606,846,976 bytes — about 15.3% larger. This is the largest practically relevant gap between SI and IEC units in storage contexts. For a data center procuring 10 EB of storage, the SI vs IEC difference represents about 1.5 EB of capacity discrepancy in the contract.

Data archaeology is the practice of recovering information from obsolete storage media and formats — 9-track magnetic tapes, 8-inch floppy disks, MiniDiscs, Zip drives, and early optical formats. The challenge is threefold: hardware to read the media no longer exists or is failing, file formats and encoding schemes are undocumented, and magnetic media degrade over time (tape has a 10–30 year shelf life). At exabyte scale, organisations like national archives face the prospect of vast digital collections becoming unreadable within decades. Active migration strategies — periodically copying data to current formats and media — are the only reliable defense, but the cost scales linearly with data volume.

PB (petabyte) = 10¹⁵ bytes = 1,000,000,000,000,000 bytes (SI decimal). PiB (pebibyte) = 2⁵⁰ bytes = 1,125,899,906,842,624 bytes (IEC binary). PiB is 12.59% larger. For a data center purchasing 100 PiB of raw storage, the SI vs IEC confusion would represent approximately 12.59 PB of missing or unexpected capacity.

Cloud providers (AWS, Azure, GCP) operate at exabyte scale but provision and bill individual customers at PiB scale for enterprise storage. Scientific computing facilities like CERN, the Square Kilometer Array telescope project, and US national laboratories store tens to hundreds of PiB. Large video platforms (Netflix, YouTube) store hundreds of PiB of encoded video content.

Using 20 TB drives (a 2024 high-density consumer drive): 1 PiB = 1,125,899,906,842,624 bytes ÷ 20,000,000,000,000 bytes/drive ≈ 56.3 drives. So roughly 57 × 20 TB drives to fill 1 PiB. In a data center using 60-drive storage shelves, one shelf of 60 × 20 TB drives provides about 1.07 PiB of raw capacity.

Magnetic tape (LTO technology) remains the dominant medium for cold storage at PiB scale due to economics and durability. An LTO-9 cartridge holds 18 TB (uncompressed) and costs roughly $100 — about $5.50 per TB, versus $15–20 per TB for HDDs. Tape also consumes zero power when idle, unlike spinning disks. The IBM TS4500 tape library can hold over 40 PiB in a single rack. Major users include CERN, national archives, and film studios — Netflix stores its master copies on tape. Tape's main downside is sequential access: retrieving a specific file can take minutes versus milliseconds for disk.

CERN's Worldwide LHC Computing Grid stores approximately 300–400 PB (petabytes, decimal) of data across distributed sites, with the main Tier-0 facility at CERN holding about 100 PB on disk and 200 PB on tape. The LHC generates roughly 15 PB of data per year from collision events. Future upgrades (High-Luminosity LHC) are projected to increase this to 50–100 PB per year.