---
id: taking-a-snapshot
+since: 2.3
---
The normal behavior of LTTng is to record trace data as trace files.
or stopped, you may take a snapshot of those sub-buffers.
There is no difference between the format of a normal trace file and the
-format of a snapshot: viewers of LTTng traces will also support LTTng
+format of a snapshot: viewers of LTTng traces also support LTTng
snapshots. By default, snapshots are written to disk, but they may also
be sent over the network.
</pre>
Next, enable channels, events and add context to channels as usual.
-Once a tracing session is created in snapshot mode, channels will be
-forced to use the overwrite mode (`--overwrite` option of the
-`enable-channel` command) and have an `mmap()` channel type
+Once a tracing session is created in snapshot mode, channels are
+forced to use the
+[overwrite](#doc-channel-overwrite-mode-vs-discard-mode) mode
+(`--overwrite` option of the `enable-channel` command; also called
+_flight recorder mode_) and have an `mmap()` channel type
(`--output mmap`).
Start tracing. When you're ready to take a snapshot, do:
lttng snapshot record --name my-snapshot
</pre>
-This will record a snapshot named `my-snapshot` of all channels of
+This records a snapshot named `my-snapshot` of all channels of
all domains of the current tracing session. By default, snapshots files
are recorded in the path returned by `lttng snapshot list-output`. You
may change this path or decide to send snapshots over the network
lttng snapshot record --name my-snapshot --max-size 2M
</pre>
-Older recorded events will be discarded in order to respect this
+Older recorded events are discarded in order to respect this
maximum size.