Privacy policy

Linux Labs is a trainer for learning Linux administration on real virtual machines. This page explains what data we collect, why we need it and what you can do about it.

What works without signing in

The textbook, the reference, lab descriptions and quiz previews are open to everyone and need no account. To tell one visitor from another, your browser receives a random technical identifier in a cookie. It is not tied to your name or email, and it exists only so that your own virtual machine and your own progress come back to you before you sign in. While you only read, nothing is recorded under this identifier: guest progress starts being saved with the first action — an answer, a check, a bookmark, a language switch. How long guest data is kept is described under "Retention".

What appears after signing in

Virtual machines, lab checking, hints and saved progress require signing in with Google. From your Google profile we receive and store:

• email address, which identifies the account;
• name, so that pages can address you;
• Google account number, an internal identifier that lets sign-in recognise you next time. On its own it tells nothing about you.

We do not request access to your mail, documents, contacts or any other Google service. Your Google password never reaches us: the sign-in happens on Google's side, and we receive only the confirmation and the data above.

What we store about your learning

Progress through lessons, labs and quizzes: which steps are done, when, how many attempts and hints there were, which lab goals were met at the last check, and when a review is due. These records exist so that your learning plan resumes where you left off.

Each time you check a lab we record when it happened, how many goals were met and what the check reported about the first goal that was not — this makes up the «Solution history» in your profile. For a guest these records are tied to the browser's technical identifier, for a signed-in learner to the account, and they are deleted together with it.

Once you sign in, we also remember which reference articles you visited and the section you stopped at, one record per article, so we can offer to take you back there. A guest's reading position is not stored.

Notes and bookmarks are what you wrote down and marked yourself. A note is your text for a lab, one per lab (up to 10,000 characters), and when it was last saved; a bookmark is what it points to (an article, a cheat sheet line, a recipe, a term or a lab) and when it was set. We show them only to you: a note in the «Note» tab of the lab, in the «Solution history» and in your profile, bookmarks in your profile and as stars on the pages; other learners and the public pages never see them. They are saved only by your own action — typing the note and clicking the star. For a guest they are tied to the browser's technical identifier and move to the account on sign-in, for a signed-in learner they are tied to the account and deleted together with it. You can delete a note in your profile at any time and remove a bookmark with the same star.

About virtual machines we keep when a machine was started, when you last worked with it and why it is gone (you stopped it, it expired, it sat idle, it failed). What you did on the machine is kept only as described in the next two sections.

Terminal recording

Once you sign in, the lab terminal is recorded: everything that appeared on its screen is kept — the machine's output and the commands you typed as the machine displayed them, with timestamps. Keystrokes are not recorded separately, so whatever the machine does not print (a password typed into sudo, for example) does not get into the recording. The recording lets you play back your solution in the «Solution history»; the check marks on its timeline come from the check records. A guest's terminal and the sandbox are not recorded. While the terminal is being recorded, its bottom line shows a «recording» mark.

Only you can see a recording: anyone else following a link to it gets «page not found». It is kept for 90 days from the start of the session and then deleted automatically. One session holds at most 512 KB of text — beyond that the recording stops. Recording is on by default; you can turn it off in your profile, under «Settings», with the «Record the terminal» switch. Once it is off nothing new is saved, including from a terminal that is already open; earlier recordings stay until their term ends or the account is deleted.

Last commands

When a machine is removed after inactivity or when the session expires, the trainer may read the last ten shell commands from it, so that the lab screen and «Continue» on the home page remind you where you stopped. The commands are kept until you start this lab again, for no longer than 90 days, are visible only to you (to a guest — in this browser) and are deleted together with the account. A machine you finished yourself is not read this way.

Feedback and tickets

When you write through the feedback form, we keep the ticket: its type (error, suggestion, question), your text and the conversation about it, the address for the reply if you gave one (for a signed-in learner — the account address, which can be replaced in the form), and what the ticket is about. That part is filled in by itself: the article or lesson and its section, the fragment you selected, the lab, the machine name and when it started, the quiz question and the answer you chose, the search query, the broken address and the page linking to it, the page you wrote from and the site version.

A ticket from a lab carries the last 200 lines of the terminal by default — what was on the screen; the box can be unticked, and “See what will be sent” shows the lines beforehand. Passwords, tokens and private keys are cut out of them on the server before saving. The check results of that machine are attached the same way, with a box. The terminal recording of the session is attached only if you tick a separate box for it yourself: the recording is kept as it is, nothing is cut out, and the course author will see it.

The ticket is visible to you — in the profile, in the “Tickets” section (a guest sees it in this browser) — and to the course author. Other learners and public pages do not show tickets. The author may add an internal note to a ticket — only the author sees it. The author's reply, “Fixed” and “Declined” come as a notification on the site and as an email if you have it on — see “Notifications and emails”.

A ticket of an account is kept for as long as the account exists and is deleted with it; when you sign in, the guest tickets of this browser move to the account. A guest ticket is deleted 180 days after its last message. The attached terminal lines and check results are deleted 90 days after the ticket is closed.

Notifications and emails

The trainer tells you about what concerns your learning: the author's reply to a ticket, “Fixed” or “Declined” on your report, a review reminder (once a week, if there is something to review), a new lab in a track you started, scheduled maintenance, a machine that was stopped for inactivity or did not come up, and mailings from the course author. Notifications are shown by the bell in the site header and on the “All notifications” page; a guest sees theirs in this browser — by the same identifier in the cookie — and they move to the account on sign-in. A notification is kept for 90 days, a pinned maintenance notice — until its date.

Emails go only to an account — to the email address received from Google at sign-in. The address typed into the feedback form is seen only by the author, to reply personally: no automatic emails go there. A guest has no address and gets no emails. You decide what to send and where: in the profile, in “Settings · Notifications”, every kind has its own “on the site” and “by email” switch, and changes apply at once. By default only replies to tickets and scheduled maintenance come by email, the rest stays on the site until you turn emails on yourself. Notifications about scheduled maintenance and about the machine cannot be turned off on the site: without them it is unclear why a lab is unavailable.

Mailings from the author — about new tracks and changes in the project — are emailed only to those who turned on “From the author · by email” themselves; otherwise a mailing is shown only by the bell. Every email has an “Unsubscribe” link: it turns off emails of that kind without signing in, while the notifications on the site stay. Several notifications within an hour come as one email.

To send emails we keep an email queue: the address, the subject, the text and whether the email was sent. Its records are deleted after 90 days, and at once together with the account. Emails go through the site owner's mail server on the dimsanych.ru domain; addresses are not passed to mailing services or anyone else. Emails have no open counters and no link tracking.

Device sessions and settings

When you sign in, the trainer remembers the session of this device, so that "Settings · Sessions" shows where you are signed in and lets you sign out: on one device or on all but the current one at once. For this it keeps the browser and system label ("Windows · Firefox 130", built from the User-Agent header; the header itself is not saved), a truncated network address — the first two numbers of an IPv4 address or the first two groups of IPv6 (95.31.x.x) — and the times of signing in and of the last activity. The full address is not recorded and no city is derived from it: addresses are not passed to any external service. Signing out on another device does not stop machines in labs. A session without activity is closed after 30 days and its record is deleted.

Account settings — the terminal font size, tips at the terminal, the question before resetting a machine and terminal recording — are kept with the account. A guest has none: the theme, the font size and the tips are remembered by the guest's browser.

Downloading your data

In "Settings · Data" all your data can be downloaded as one JSON file: progress and quizzes, the history of checks, the learning log, machine sessions with their last commands, notes, bookmarks, tickets with the conversation, notifications, the email queue, settings and device sessions. Terminal recordings are included as links to the player: the recordings themselves can be large and open while they are kept. The author's internal note on a ticket is not included: it is not your data. A guest downloads what is recorded for the cookie of their browser; there is nobody else's data in the file.

Virtual machines

Every training machine is created for you and is short-lived: it is destroyed with everything inside when you stop it, after ten minutes of inactivity, or when the session expires. These machines have no access to the internet or to the home network. Anything you create inside disappears with the machine, so do not keep anything valuable there and do not type real passwords.

Visit statistics

To understand whether people come and get to the actual work, the site keeps a learning log and its own visit statistics. Both live on this server: there are no external analytics systems, third-party counters or scripts on the site.

The learning log records signing in, opening a lesson, starting a machine, completing an exercise, solving a lab and passing a quiz: which step, which lesson or lab, when and whose — your account or the guest cookie. Nothing you type goes into the log. The site owner only looks at totals from it: how many learners there were in a week, how many of them started machines and solved labs. The log is part of the data download and is deleted together with the account.

Visit statistics are anonymous and work with no cookies: a small script of the site (/_/p.js) tells this same server that a page was viewed and how long it was used. The statistics record:

• the page address — without the part after #; parameters that look personal (email, tokens, keys, codes, passwords, phone numbers) are cut out, and in fact everything except the utm_* campaign tags, the page and step number and the site search query;
• where the visit came from: the site and path of the referring page, the kind of source (search engine, social network, AI assistant, email, another site, direct visit) and the utm_* campaign tags;
• the device type, browser and system — derived from the User-Agent header, which itself is not stored; the window width as one of four steps; the browser language; the country — from the browser's time zone, with no city and no IP address databases;
• how long the page was open and in use, how far it was scrolled, how fast it loaded (Web Vitals) and whether the page was not found;
• clicks on links to other sites (their domain only), file downloads and learning steps — the same as in the log, but without your identifier.

What the statistics do not have: cookies, localStorage or other marks in the browser, browser fingerprints, your name, email, learner or account identifier. The IP address is not stored: to count unique visitors per day, the server takes a hash of the IP address, the browser string (User-Agent) and a random salt of that day, and the salt is deleted after a day — visits of different days cannot be linked and the address cannot be recovered from the hash. Robots and automated browsers are not counted by the script, and neither is the site staff.

Visit records are kept for 90 days; after that only daily totals remain — numbers per day (how many visitors, visits and page views there were), with no individual visits. The statistics collect no personal data, so the site asks for no consent for them and shows no cookie banner. If you prefer not to take part, block the /_/p.js address in your browser: learning works the same.

So that a learning step that happens on the way to another page (signing in, for example) reaches the statistics, the site puts its name — and nothing else — into the labs_goal cookie for five minutes; the statistics script reads it and erases it at once.

What we do not do

We show no advertising, we do not share or sell your data, we connect no external analytics, and we build no advertising profiles. The data serves the trainer and nothing else.

What you search for

Site search counts queries to show newcomers what people look for most often («Popular searches» on the Wiki home page). A query counts once you open the search page with it or follow a result. Only the query text, the language, the day and how many times it was searched that day are stored — no identifier, address or account of yours. Repeating the same query from the same browser within a day does not count. Queries with typos or words that do not appear on the site are not recorded at all, and rare queries are never shown to anyone. Counters older than thirty days are deleted.

Retention

Progress records, the learning log, notes, bookmarks, tickets and notification settings are kept for as long as your account exists (or until you delete them); guest tickets — 180 days after the last message. Notifications and the email queue — 90 days, device sessions — 30 days after the last activity. Terminal recordings are kept for 90 days from the start of the session, the last commands of a removed machine until you start that lab again but no longer than 90 days. Server logs, which record page addresses and request times, are kept for no longer than thirty days and are used to investigate failures. Visit statistics records are kept for 90 days, after which only daily totals without individual visits remain; the salt for counting unique visitors lives for a day.

A guest is a browser without a sign-in. A guest profile is created by the guest's first action. 90 days after a guest's last visit, the guest profile and its data are deleted: progress, attempts, notes, bookmarks, notifications and device sessions; learning log records lose their link to the browser and remain only in the totals. The deletion runs automatically on a schedule. Guest tickets stay with the course author without a link to the browser and are deleted on their own term — 180 days after the last message.

How to delete your account

You can delete your account in "Settings · Data". The confirmation window lists, with numbers, what will be deleted and links to the download; the deletion starts only when the word "delete" is typed in the field, and the server checks it too. The email address, the name, every progress record, the learning log, the notes, the bookmarks, the tickets, the notifications, the email queue, the terminal recordings, the last commands, the settings and the device sessions go with the account: you are signed out on every device at once. Running machines are stopped before the deletion. Signing in with Google afterwards creates a new empty account. If something goes wrong, write to the site owner and the account will be deleted by hand.

Changes

If we ever start collecting anything else, this page will change before that happens, and the date at the top will be updated.