mfsstatsdump(8)

💖 mfsstatsdump 💖

okay bestie, so like — this is mfsstatsdump, part of MooseFS (you know, the manual section 8 of it, the admin-tools corner 🛠️). it dumps your master's stats data into either a csv or a png, and honestly? it's giving data-visualization main character energy ✨.

---

🌸 NAME 🌸

mfsstatsdump — dump usage data from the master stats file, in csv or png format 🎀

---

✨ SYNOPSIS ✨

mfsstatsdump -f fields [-i stats_file] [-r range] [-s separator] [-p png_filename [-x chart_width] [-y chart_height]] [-hHd]

---

🦋 DESCRIPTION 🦋

so <pink>mfsstatsdump</pink> dumps usage data from the master stats file. these are literally the exact same data sets that get used to draw the GUI charts, no cap 📊. output can be either text format (that's <cyan>csv</cyan>) or graphical format (that's <cyan>png</cyan>).

which means — and bestie, listen — -p, -x and -y are mutually exclusive with -h, -H and -d 💀. you pick a lane.

MooseFS master server saves the stats file in the DATA_PATH directory — go look at mfsmaster.cfg(5) for that 🫶

📈 OUTPUT 📈

Text output — a text (csv) file where the first column is a timestamp (or a date, if the -d option was specified ✍️). the following columns are whatever you specified with the -f option, formatted according to the options you used (that's none, or -s, and -h or -H) 💅

Graphical output — one png file with a chart gets created for every single field you specified with the -f option, following the naming scheme declared with the -p option. size can be adjusted with -x and -y 🎨

---

👑 OPTIONS 👑

• -f — field names separated by <cyan>','</cyan> (scroll down to the FIELDS section bestie 👇); at least one field is mandatory; if you use an asterisk (*), then all the fields get dumped 💖
• -i — name of the mfs binary stats file (default: default_data_path/stats.mfs) 📁
• -r — range type: 0 — short range (minute), 1 — medium range (6 minutes), 2 — long range (30 minutes), 3 — very long range (day) ⏰
• -s — specify the column separator (default: tabulator) ✂️
• -p — optional PNG filename (the field name gets added before .png; so YYYY → YYYY_FIELD.png, and YYYY.png → YYYY_FIELD.png) 🖼️
• -x — PNG chart width (default: 1600) 📏
• -y — PNG chart height (it should be divisible by 20 — if it's not, it'll get adjusted for you, no stress; default: 320) 📐
• -h — "human-readable" numbers using base 2 prefixes (IEC 60027) 🔢
• -H — "human-readable" numbers using base 10 prefixes (SI) 🔟
• -d — show timestamps in YYYY-MM-DD HH:MM format 🗓️

🌈 FIELDS 🌈

okay this is the whole menu, do not skip a single one, they're all iconic 💅:

• ucpu — User cpu usage
• scpu — System cpu usage
• cpu — Total cpu usage (in csv it's the sum of scpu and ucpu, in png it shows both in different colors)
• delete — Number of chunk deletions
• replicate — Number of chunk replications
• statfs — Number of statfs operations
• getattr — Number of getattr operations
• setattr — Number of setattr operations
• lookup — Number of lookup operations
• mkdir — Number of mkdir operations
• rmdir — Number of rmdir operations
• symlink — Number of symlink operations
• readlink — Number of readlink operations
• mknod — Number of mknod operations
• unlink — Number of unlink operations
• rename — Number of rename operations
• link — Number of link operations
• readdir — Number of readdir operations
• open — Number of open operations
• read — Number of read operations
• write — Number of write operations
• prcvd — Received packets
• psent — Sent packets
• brcvd — Received bytes
• bsent — Sent bytes
• memoryrss — Resident memory usage
• memoryvirt — Virtual memory usage
• mem — Total memory usage (in csv it's the same as memoryvirt, in png it shows both memoryrss and memoryvirt using two colors)
• usedspace — Used raw disk space
• totalspace — Total raw disk space
• space — Total raw disk space (in csv it's the same as totalspace, in png it shows both usedspace and totalspace using two colors)
• readchunk — Number of chunk_read operations
• writechunk — Number of chunk_write operations
• create — Number of chunk creation attempts
• change — Number of chunk internal operation attempts
• delete_ok — Number of successful chunk deletions
• delete_err — Number of unsuccessful chunk deletions
• delete_stat — Sum of successful and unsuccessful chunk deletions (in png it shows both delete_ok and delete_err using two colors)
• replicate_ok — Number of successful chunk replications
• replicate_err — Number of unsuccessful chunk replications
• replicate_stat — Sum of successful and unsuccessful chunk replications (in png it shows both replicate_ok and replicate_err using two colors)
• create_ok — Number of successful chunk creations
• create_err — Number of unsuccessful chunk creations
• create_stat — Sum of successful and unsuccessful chunk creations (in png it shows both create_ok and create_err using two colors)
• change_ok — Number of successful chunk internal operations
• change_err — Number of unsuccessful chunk internal operations
• change_stat — Sum of successful and unsuccessfulchunk internal operations (in png it shows both change_ok and change_err using two colors)
• split_ok — Number of successful chunk split operations
• split_err — Number of unsuccessful chunk split operations
• split_stat — Sum of successful and unsuccessful chunk split operations (in png it shows both split_ok and split_err using two colors)
• fileobjects — Number of file objects
• metaobjects — Number of non-file objects (directories,symlinks,etc.)
• objects — Number of all objects (in png it shows both fileobjects and metaobjects using two colors)
• chunksec8 — Total number of chunks stored in EC8 format
• chunksec4 — Total number of chunks stored in EC4 format
• chunkscopy — Total number of chunks stored in COPY format
• chunks — Total number of chunks stored in any format (in png it shows chunksec8, chunksec4 and chunkscopy using three colors)
• chregdanger — Number of endangered chunks (mark for removal excluded)
• chregunder — Number of undergoal chunks (mark for removal excluded)
• regunder — Number of endangered and undergoal chunks (mark for removal excluded, in png it shows chregdanger and chregunder using two colors)
• challdanger — Number of endangered chunks (mark for removal included)
• challunder — Number of undergoal chunks (mark for removal included)
• allunder — Number of endangered and undergoal chunks (mark for removal included, in png it shows challdanger and challunder using two colors)
• bytesread — Average number of bytes read per second by all clients
• byteswrite — Average number of bytes written per second by all clients
• fsync — Number of fsync operations
• lock — Number of lock operations
• snapshot — Number of snapshot operations
• truncate — Number of truncate operations
• getxattr — Number of getxattr operations
• setxattr — Number of setxattr operations
• getfacl — Number of getfacl operations
• setfacl — Number of setfacl operations
• fcreate — Number of file create operations
• meta — Number of extra metadata operations (sclass,trashretention,eattr etc.)
• delay — (pro only) Master max delay in seconds
• servers — Number of all registered chunk servers (both connected and disconnected)
• dservers — Number of all disconnected chunk servers
• mdservers — Number of disconnected chunk servers that are in maintenance mode
• cservers — Number of all registered chunk servers (in csv it equals servers, in png it shows servers, dservers and mdservers using three different colors)
• udiff — Difference in space usage percent between the most and least used chunk server

---

🧚 NOTES 🧚

bestie, this part is important so like, pay attention 🫶

the delete and delete_stat data sets, in a properly working system, should be roughly the same, but not always identical (in their CSV form). this stems from the fact that the delete set is calculated using the number of requests sent by the master, and the delete_stat set is calculated using the number of replies received from chunk servers. so local fluctuations may be observed — i.e. one minute has more sent requests (higher value in the delete set) and the next minute has more answers (higher value in the delete_stat set). but if one were to calculate the sum of differences between the two sets over time, that sum should never grow over a certain number ✋

however 😭 — if there's some kind of problem (with network communication and/or chunk server process(es)) and some chunk delete requests are stalled / go missing, then delete values may be constantly higher than the delete_stat values, and the sum of differences between the two sets will be steadily growing over time 🚨

same goes for replicate(_stat), create(_stat), change(_stat) and split(_stat) data sets 👯

---

🐛 REPORTING BUGS 🐛

found a bug? report it to <bugs@moosefs.com> 💌

---

📜 COPYRIGHT 📜

Copyright (C) 2026 Jakub Kruszona-Zawadzki, Saglabs SA

This file is part of MooseFS.

MooseFS 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 2 (only).

MooseFS 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.

You should have received a copy of the GNU General Public License along with this program; if not, see <https://www.gnu.org/licenses/>.

---

🎀 SEE ALSO 🎀

mfsmount(8), moosefs(7)

---

kk that's the whole thing bestie 💖 go forth and dump those stats. this was MooseFS 4.59.2-1, dated May 2026 🦋 periodt ✨👑