Hands-on steps to reserve, mount and use Linux hugepages for low-latency workloads 29.11.2025 | reading time: 3 min Hugepages reduce TLB pressure and improve performance for databases, VMs and network stacks; this guide shows how to reserve pages, mount hugetlbfs and allocate them with concrete commands so the administrator can replicate the steps. Reserve and allocate concrete pages Check the default hugepage size with `grep Hugepagesize /proc/meminfo`; reserve 4 two-megabyte pages with `echo 4 | sudo tee /proc/sys/vm/nr_hugepages`; create a mount point and mount hugetlbfs with `sudo mkdir -p /mnt/huge && sudo mount -t hugetlbfs -o pagesize=2M none /mnt/huge`; allocate the pages by writing a file with `sudo dd if=/dev/zero of=/mnt/huge/testfile bs=2M count=4`; verify reservation before allocation with `grep HugePages_Total /proc/meminfo` which should show `HugePages_Total: 4` and after the dd the free counter will drop so `grep HugePages_Free /proc/meminfo` shows `0`. Per-size controls and one-gigabyte pages For nondefault sizes use the sysfs entries under `/sys/kernel/mm/hugepages/`, for example `echo 2 | sudo tee /sys/kernel/mm/hugepages/hugepages-1048576kB/nr_hugepages` reserves two 1G pages on a CPU that supports them; mount with `sudo mount -t hugetlbfs -o pagesize=1G none /mnt/huge1G` to use 1G files; remember that 1G pages require hardware support and reduce available normal memory in large lumps. Make settings persistent and boot-time allocation Persist runtime reservations by placing `vm.nr_hugepages=4` in `/etc/sysctl.d/99-hugepages.conf` or reserve at boot with kernel parameters like `hugepagesz=1G hugepages=2` added to the boot loader; mount hugetlbfs automatically with an fstab line such as `none /mnt/huge hugetlbfs pagesize=2M 0 0` to restore the mount after reboot. Practical caveats and when to disable THP Transparent Huge Pages is a separate feature and can collide with static hugepages; for predictable performance disable THP with `echo never | sudo tee /sys/kernel/mm/transparent_hugepage/enabled` for workloads that demand explicit hugepage control; always plan allocations because reserved hugepages cannot be reclaimed for normal use without freeing them first. Related utilities and monitoring Use `numactl` to control placement across NUMA nodes, `perf` to measure TLB misses and latency, and `sysctl` to script and audit vm settings; monitoring `/proc/meminfo` and `/sys/kernel/mm/hugepages` shows current usage and helps tune counts against application requirements. Next steps for the administrator Try reserving pages on a test machine, mount hugetlbfs, allocate them from a sample application and observe latency improvements; once comfortable, make the configuration reproducible via sysctl files or boot parameters and integrate checks into deployment automation. Join Bits & Bytes Academy First class LINUX exam preparation. setup processes virtualization
