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How to Set Up a RAM Disk (tmpfs) for High-Speed I/O

By Admin · Mar 15, 2026 · Updated Apr 23, 2026 · 186 views · 1 min read

A RAM disk uses system memory as a filesystem, providing extremely fast I/O — orders of magnitude faster than even NVMe SSDs. tmpfs is the standard Linux mechanism for creating RAM-based filesystems, and it is already used by the system for /tmp, /run, and /dev/shm.

Understanding tmpfs

# tmpfs filesystems already on your system:
df -h -t tmpfs
# Filesystem      Size  Used  Avail  Use%  Mounted on
# tmpfs           793M  1.2M   792M    1%  /run
# tmpfs           3.9G     0   3.9G    0%  /dev/shm
# tmpfs           5.0M  4.0K   5.0M    1%  /run/lock

# Key characteristics:
# - Stored in RAM (and swap if configured)
# - Data lost on reboot
# - Dynamically sized (only uses RAM for actual content)
# - No wear on SSDs
# - Extremely fast: >10 GB/s throughput,

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