.NET Dump Cheat Sheet
09/28/2025 | 2 minutes to read
This post collects some useful commands diagnosing memory dumps. This document is written with a sample apps and tools targeting .NET 9. Some tools still name regions as segments.
dotnet-dump
Use dotnet-dump to collect a memory dump.Install using dotnet tool install dotnet-dump -g
It can do full dump/mini dump, etc.
dotnet-gcdumpwhile really similar creates a dumps that contains only the count and size of objects per class and the references between types to the roots.
With dotnet-dump collect a Heap dump is usually the best choice which (it does not contain 'images' (the DLLs) that is only in the full dump).
For example, collect Heap dump for process ID 420 that is running with elevated privileges:
sudo -E DOTNET_ROOT=/home/Home/.dotnet /home/Home/.dotnet/tools/dotnet-dump collect --type Heap -p 418Notice that the -E exports the DOTNET_ROOT environment variable.
Use dotnet-dump analyze to analyze the dump. This offers the same SOS commands for the analysis as one might have used with WinDBG.
For example, let's find the address of a C# string literal Hello in the dump. the string literal is used in an anonymous method.
I am going to analyze the previously save dump file
dotnet-dump analyze core_<date>_<hours>Find the anonymous method
name2ee (return a MT entry for a given type name)
eeheap (displays the heaps/regions of the app)
gcwhere (displays the heap/region informtion of an object)
dumpheap (display all objects and types allocated with memory addresses)
gcroot (display the reference path to roots)
threads (display threads)
syncblk (for analyzing locks)
dumpmt (display method table)
dumpmd (display method descriptor)
d (read memory)
eestack (stacks)
Others useful tips:
Add .NET and .NET tools to the path, for example:
nano ~/.bashrc
...
export DOTNET_ROOT=$HOME/.dotnet
export PATH=$PATH:$HOME/.dotnet:$HOME/.dotnet/tools