Hi everyone,
I’m facing a recurring issue with the WAGO CC100 Edge Controller related to SD card detection after rebooting the system.
Setup & steps taken:
- Controller: WAGO CC100
- SD card formatted using the Web-Based Management (WBM) interface:
WBM > Mass Storage > Create New Filesystem on Memory Card
- Initially, the SD card is recognized correctly, full capacity is shown – everything seems fine.
df -h
displays the SD card as expectedfdisk -ul
also shows the correct layout
Issue: After rebooting the controller (reboot
), the SD card is intermittently not recognized correctly.
Roughly 50% of the time, it doesn’t show up after boot.
dmesg | grep mmc
output shows:
[ 0.998435] mmc0: new SD card at address d555
[ 1.004944] mmcblk0: mmc0:d555 SD032 30.6 MiB
→ It identifies the card, but only as 30.6 MiB, even though it’s a 32GB card.
df -h
output shows:
Filesystem Size Used Available Use% Mounted on
/dev/root 581.4M 187.8M 351.1M 35% /
devtmpfs 246.6M 12.0K 246.6M 0% /dev
none 247.1M 8.0K 247.1M 0% /tmp
none 247.1M 156.0K 247.0M 0% /media
none 4.0M 124.0K 3.9M 3% /var/log
none 247.1M 136.0K 247.0M 0% /var/run
none 247.1M 0 247.1M 0% /var/lock
none 247.1M 0 247.1M 0% /var/tmp
none 247.1M 0 247.1M 0% /sys/fs/cgroup
tmpfs 247.1M 168.0K 246.9M 0% /run
/dev/mmcblk1p2 16.0M 644.0K 15.3M 4% /boot/loader
/dev/mmcblk1p6 1.1G 184.4M 851.4M 18% /home
/dev/mmcblk1p4 6.7M 45.0K 6.1M 1% /settings
/dev/mmcblk1p3 6.7M 45.0K 6.1M 1% /log
none 247.1M 136.0K 247.0M 0% /var/run/netns
none 247.1M 156.0K 247.0M 0% /media/sd/docker
where /media/sd/docker
usually should be mounted on /dev/mmcblk0p1.
Also, fdisk -ul
output shows:
Disk /dev/mmcblk0: 30 MB, 32096256 bytes, 62688 sectors
979 cylinders, 4 heads, 16 sectors/track
Units: sectors of 1 * 512 = 512 bytes
Disk /dev/mmcblk0 doesn't contain a valid partition table
Disk /dev/mmcblk1: 3728 MB, 3909091328 bytes, 7634944 sectors
473 cylinders, 256 heads, 63 sectors/track
Units: sectors of 1 * 512 = 512 bytes
Device Boot StartCHS EndCHS StartLBA EndLBA Sectors Size Id Type
/dev/mmcblk1p1 0,0,2 1023,255,63 1 7634943 7634943 3727M ee EFI GPT
Partition 1 has different physical/logical end:
phys=(1023,255,63) logical=(473,101,37)
where I can find that Disk /dev/mmcblk0
has issues with the partition table – issues that may have been caused during formatting via the WBM or the corresponding command:
/etc/config-tools/format_medium device=mmcblk0 volume-name=docker-sd fs-type=ext4
?
Technical insight – format_medium script behavior:
During formatting via the WBM or using the manual command
/etc/config-tools/format_medium device=mmcblk0 volume-name=docker-sd fs-type=ext4
,
the script internally uses the following line to partition the device:
echo ",,${part_type},," | flock "$deviceName" sfdisk -f "$deviceName" > /dev/null 2>&1
Here’s what this does:
sfdisk
is used to write a new partition table to the device.",,${part_type},,"
tellssfdisk
to:- create one partition using the entire available space (no start or end sector specified),
- with the partition type determined by the selected filesystem:
"83"
for ext4"b"
for FAT32
flock
ensures that no other process is accessing the device during this operation.- This partitioning step happens after deleting any existing GPT or MBR, and before formatting with
mkfs
.
This reinforces my suspicion that the issue may not lie in how the partition is created, but rather in how the system (CC100) picks it up during or after boot – especially given that GParted consistently shows everything as expected.
What I’ve tried so far:
- Multiple CC100 controllers
- Multiple SD cards (different delivery batches)
- Same issue: the card is either detected correctly or not – it’s inconsistent
Additionally: I’ve already tried the suggestions from this community thread, which mainly focuses on issues with the Docker daemon startup, related to the “delayed” SD card recognition:
- Set
timeout=20
(instead of 10) in/usr/local/bin/wago-automount
- Added
sleep 180
in/etc/init.d/dockerd
Unfortunately, this hasn’t helped – the issue persists.
Extra observation:
When I take an SD card that was not recognized properly by the CC100 (or shows only 30.6 MiB and no partition), and plug it into another system and check it with GParted, I can see the full capacity (32 GB). The partition is there, and it’s properly formatted as ext4 – everything looks normal from an external system’s perspective.
Important note:
We are not using the official WAGO-branded SD card.
However, we have now provisioned over 300 CC100 controllers with the same 32 GB micro SD cards and identical setup / identical setup procedure, and this issue has only started appearing this week.
My questions:
- Why would the SD card sometimes be detected as only 30.6 MiB?
- Any way to make the mount process more reliable during boot? We are using FW Version 04.01.10(23) - could this issue be fixed using a more recent FW Version?
- Any tricks for formatting or automounting that might help?
Any help or insights would be greatly appreciated!
Best regards