How to troubleshoot slow booting

Creating a bug report/issue

I have searched the existing open and closed issues

Required Information

  • DietPi version |
G_DIETPI_VERSION_CORE=9
G_DIETPI_VERSION_SUB=7
G_DIETPI_VERSION_RC=1
G_GITBRANCH='master'
G_GITOWNER='MichaIng'
  • Distro version | bookworm
  • Kernel version | Linux hostname 6.10.11+bpo-amd64 #1 SMP PREEMPT_DYNAMIC Debian 6.10.11-1~bpo12+1 (2024-10-03) x86_64 GNU/Linux
  • Architecture | amd64
  • SBC model | Native PC (x86_64)
  • Power supply used | N/A
  • SD card used | N/A

Extra details

Actually this is not a real bug, but rather an issue I’m having (and I’m having issues debugging it).
The boot got significantly slower, but I did not notice when it became slower. The boot time was rougly 15 seconds and now it is more than one minute.

This is the dmesg output of the part I consider the most interesting:

[    5.474607] Bluetooth: hci0: Found Intel DDC parameters: intel/ibt-19-0-3.ddc
[    5.477081] Bluetooth: hci0: Applying Intel DDC parameters completed
[    5.478056] Bluetooth: hci0: Firmware revision 0.3 build 15 week 45 2022
[    5.479955] Bluetooth: hci0: HCI LE Coded PHY feature bit is set, but its usage is not supported.
[    8.710950] wlan0: authenticate with <other mac address> (local address=<local mac address>)
[    8.712109] wlan0: send auth to <other mac address> (try 1/3)
[    8.739791] wlan0: authenticated
[    8.741010] wlan0: associate with <other mac address> (try 1/3)
[    8.742816] wlan0: RX AssocResp from <other mac address> (capab=0x1011 status=0 aid=4)
[    8.753558] wlan0: associated
[    8.823158] wlan0: Limiting TX power to 23 (23 - 0) dBm as advertised by <other mac address>
[   67.106596] EXT4-fs (dm-0): mounted filesystem <uuid of external ssd> r/w with ordered data mode. Quota mode: none.
[   67.468804] evm: overlay not supported
[   68.985765] Initializing XFRM netlink socket
[   69.027438] bridge: filtering via arp/ip/ip6tables is no longer available by default. Update your scripts to load br_netfilter if you need this.
[   70.041535] docker0: port 1(veth835e0ac) entered blocking state
[   70.041543] docker0: port 1(veth835e0ac) entered disabled state

As you can see, between connecting to the wifi and the mounting of the external SSD drive there is a significant delay.

For your information, the partition that gets mounted at 67.106596 is the one with the dietpi userdata folder.

However from the dmesg output I cannot understand why the system idles for roughly one minute, so my questions are:

  • Is the mounting process the real cause for the delay or there is/may be something else?
  • How can I get additional info so that I can fully understand what is blocking the boot process?
  • Is there any way to find a workaround (e.g. reduce a retry timeout to make it happen faster)?

I know there are probably not enough information to answer the specific question in this post, but actually I’m looking for ways to troubleshoot and to gather additional info rather than a specific fix.

There are a couple of commands you can use to analyse the situation

systemd-analyze blame
systemd-analyze critical-chain
systemd-analyze plot > /tmp/blame.svg

Last one will create a picture that can download to your desktop computer.

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So useful. Thanks. From blame it seems that is because of eth0, which is currently unused (since device is connected on WiFi)

1min 1.630s ifup@eth0.service
     6.350s ifup@wlan0.service
     1.418s ifupdown-pre.service
      593ms dev-sdb2.device
      501ms smartmontools.service

I disabled eth0 through dietpi-config and now boot time went down to 30 seconds :grin: thank you so much

1 Like