diff --git a/archlinux.md b/archlinux.md
index 0106193..107db51 100644
--- a/archlinux.md
+++ b/archlinux.md
@@ -15,3 +15,9 @@ journalctl --disk-usage && journalctl --vacuum-size={size}M
 ```
 or prepare the file`/etc/systemd/journald.conf` and this value:`SystemMaxUse=50M`
 
+create for all btrfs filesystems a regulary scrub timer.
+```bash
+for p in $(lsblk -nflo FSTYPE,MOUNTPOINT | awk '$1=="btrfs"{print $2}'); do systemctl enable --now "btrfs-scrub@$(systemd-escape -p "$p").timer"; systemctl start "btrfs-scrub@$(systemd-escape -p "$p").service"; done
+```
+the manual way of creating is eating the correct escape.
+
diff --git a/edms.md b/edms.md
new file mode 100644
index 0000000..33f2185
--- /dev/null
+++ b/edms.md
@@ -0,0 +1,10 @@
+# EDMS
+
+mayan
+paperless-ng
+ocrmypdf
+Hardware-OCR
+
+## OCR
+
+## Dateihandling
diff --git a/fairphone4.md b/fairphone4.md
new file mode 100644
index 0000000..4951c2c
--- /dev/null
+++ b/fairphone4.md
@@ -0,0 +1,16 @@
+---
+keywords:
+  - IT
+---
+## Fairphone 4
+https://forum.fairphone.com/t/fp4-debloat-guide-for-better-privacy-security-and-battery-life/80003
+
+- VoLTE/Voice over WiFi maybe not working (https://forum.fairphone.com/t/how-to-enable-volte-and-wifi-calling/82049)
+- 
+
+## Android 
+https://github.com/0x192/universal-android-debloater
+   
+remove search bar from screen [not working]
+`adb shell pm uninstall --user 0 com.google.android.googlequicksearchbox`
+try this: https://lawnchair.app/
\ No newline at end of file
diff --git a/fido2.md b/fido2.md
new file mode 100644
index 0000000..5691f16
--- /dev/null
+++ b/fido2.md
@@ -0,0 +1,39 @@
+---
+keywords:
+  - IT
+  - Security
+---
+# Fido2
+### features
+- WebAuth
+    - main feature, login with username (known value by user), ChallengeResponse ( secret ) and button (interactive)/PIN
+- resident keys
+- HMAC-secret extension 
+    - symmetric key scoped to a credential
+    - https://fidoalliance.org/specs/fido-v2.0-id-20180227/fido-client-to-authenticator-protocol-v2.0-id-20180227.html#sctn-hmac-secret-extension
+## hardware
+#### OpenSK
+#### solo2
+#### nitrokey
+### code snippets
+```[https://gist.github.com/alexgwolff/5d7f6802996cad2847c4a16995da410b]
+Using resident keys If your security key supports FIDO2 resident keys*, like the YubiKey 5 Series, YubiKey 5 FIPS Series, or the Security Key NFC by Yubico, you can enable this when creating your SSH key:
+
+$ ssh-keygen -t ecdsa-sk -O resident
+
+This works the same as before, except a resident key is easier to import to a new computer because it can be loaded directly from the security key. To use the SSH key on a new computer, make sure you have ssh-agent running and simply run:
+
+$ ssh-add -K
+
+This will load a “key handle” into the SSH agent and make the key available for use on the new computer. This works great for short visits, but it won’t last forever – you’ll need to run ssh-add again if you reboot the computer, for example. To import the key permanently, instead run:
+
+$ ssh-keygen -K
+
+This will write two files into the current directory: id\_ecdsa\_sk\_rk and id\_ecdsa\_sk\_rk.pub. Now you just need to rename the private key file to id\_ecdsa\_sk and move it into your SSH directory:
+
+$ mv id\_ecdsa\_sk\_rk ~/.ssh/id\_ecdsa_sk
+
+Finally, there’s one more feature to be excited about…
+```
+## references
+https://2fa.directory/int/
diff --git a/gnuk.md b/gnuk.md
index 6d67972..c97200f 100644
--- a/gnuk.md
+++ b/gnuk.md
@@ -1,6 +1,7 @@
 ---
 keywords:
   - IT
+  - Security
 ---
 ## Gnuk
 Passport-opensc:[ https://javacardos.com/tools/passport]( https://javacardos.com/tools/passport)
diff --git a/linux_perf_problems.md b/linux_perf_problems.md
new file mode 100644
index 0000000..e5cc7e4
--- /dev/null
+++ b/linux_perf_problems.md
@@ -0,0 +1,4 @@
+# debug perfomance problems 
+https://netflixtechblog.com/linux-performance-analysis-in-60-000-milliseconds-accc10403c55
+
+introduction to ebpf: https://www.brendangregg.com/ebpf.html
\ No newline at end of file
diff --git a/linux_shell.md b/linux_shell.md
new file mode 100644
index 0000000..4d3a102
--- /dev/null
+++ b/linux_shell.md
@@ -0,0 +1 @@
+![shell-startup.png](shell-startup.png)
\ No newline at end of file
diff --git a/shell-startup.png b/shell-startup.png
new file mode 100644
index 0000000..c5ba1cf
Binary files /dev/null and b/shell-startup.png differ