LEILFS(7)

📦 version 5.12.0, in nixpkgs unstable

💅 LEILFS(7) — the leilfs girlies' guide 💅

okay so bestie, you found the man page for leilfs and honestly? you're about to have a good time. this is the LEILFS(7) page, it lives in section 7 of the manual, and it's basically the vibe-check overview of the whole filesystem. buckle up 🎀

✨ NAME ✨

leilfs — a networking, distributed, highly available file system. literally all three at once, she's an overachiever 💅

🌸 DESCRIPTION 🌸

okay so LeilFS is a networking, highly available, distributed file system. she spreads data over several physical localisations (aka servers), but from your POV as a user it's all one single resource — one directory tree, one vibe, no cap 🌈

for standard file operations, LeilFS acts like any other Unix-alike file system. she has:

  • a hierarchical structure (yes, a directory tree, we love a classic 🌳)
  • files' attributes stored properly (permissions, last access and modification times ✨)
  • the ability to create special files — block and character devices, pipes and sockets 🫶
  • symbolic links (file names pointing to another files accessible locally, not necessarily on LeilFS) 🔗
  • hard links (different names of files which refer to the same data on LeilFS) 👯

access to the file system can be limited basing on IP address and/or password. security queen 🔐

👑 distinctive features of LeilFS (her main character traits) 👑

  • higher reliability — data can be stored in several copies on separate computers 💖
  • dynamically expanding disk space — just attach new computers/disks and she grows, iconic 🌱
  • possibility of storing deleted files for a defined period of time — that's the "trash bin" service on a file system level, so your oops moments are recoverable 🙈
  • possibility of creating snapshot of a file — meaning a coherent copy of them whole file, even while the file is being written. the way that works?? obsessed 😭✨

🦋 ARCHITECTURE 🦋

okay so a LeilFS installation consists of five types of machines. five. it's giving ensemble cast 🎭

  • master metadata server (or ‘the master’) — a managing server, single computer managing the whole filesystem, storing metadata for every file (information on size, attributes and file localisation(s), including all information about non-regular files, i.e. directories, sockets, pipes and devices. she's the main character, no notes 👑
  • metadata server shadows (or ‘the shadow’) — almost identical to the master, there can be any number of those, they work as master metadata server backup and they are ready for immediate deployment as new master in case of current master failure. understudy energy, but make it mission-critical 💜
  • data servers — any number of commodity servers storing files data and replicating it among themselves (if a certain file is supposed to exist in more than one copy) 🍓
  • metadata backup servers — any number of servers, all of which store metadata changelogs and periodically downloading base metadata file; it's easy to run leil-master process on such machine when primary master stops working 🔥
  • client computers referring to LeilFS stored files — any number of machines with working leil-mount process that communicates with the managing server to receive and modify file information and with chunkservers to exchange actual file data 🫶

metadata is stored in memory of the managing server and simultaneously is being saved on disk (as a periodically updated binary file and immediately updated incremental logs). the main binary file as well as the logs are replicated to metaloggers (if present). belt and suspenders, we stan a prepared queen 💅

file data is divided to fragments (chunks) of maximum size 64MB each which are stored as files on selected disks on data servers (chunkservers). each chunk is saved on different computers in a number of copies equal to a "goal" for the given file. yes bestie, "goal" is the whole term, it's a real thing 🎯

💀 REPORTING BUGS 💀

found a bug? report bugs to the GitHub repository https://github.com/leil-io/leilfs as an issue. don't suffer in silence, the group chat wants the receipts 🐛

Copyright 2008-2009 Gemius SA

Copyright 2013-2019 Skytechnology sp. z o.o.

Copyright 2023-2024 Leil Storage OÜ

LeilFS is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 3.

LeilFS is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. like, fr fr, no warranty, read the license bestie 😤

you should have received a copy of the GNU General Public License along with LeilFS. If not, see http://www.gnu.org/licenses/. 📜

⭐ SEE ALSO ⭐

the whole friend group, go say hi 💖

and that's the page, bestie! 🎀 this one's dated 1980-01-01 and lives under LEILFS(7) — yes, the date is older than all of us, don't ask, she's iconic and she's been here forever 💅✨ go mount something, ily 🫶

📦 where this page comes from