EVE-K OS: Check Version and Boot from IMGB Partition

Overview

EVE-OS uses an A/B partition scheme with two copies of the root filesystem:

IMGA — partition 2 (primary)
IMGB — partition 3 (fallback / alternate)

The active partition is selected at boot via GPT attribute flags read by GRUB.

Check Which Partition is Currently Active

cat /run/eve.id

This returns either IMGA or IMGB.

Check the EVE Version on Each Partition

Currently Running Partition

cat /etc/eve-release

Inactive Partition (IMGB)

# Mount IMGB
mkdir -p /tmp/imgb
mount -t squashfs /dev/sda3 /tmp/imgb
 
# Read the version
cat /tmp/imgb/etc/eve-release
 
# Unmount when done
umount /tmp/imgb

Note: If your disk is not /dev/sda (e.g. NVMe), adjust accordingly.

For NVMe drives use /dev/nvme0n1p3 instead of /dev/sda3.

Partition Layout Reference

Number	Name	Size	Description
1	EFI	2.0 GiB	EFI System partition (bootloader)
2	IMGA	4.0 GiB	Primary EVE-OS root filesystem
3	IMGB	4.0 GiB	Alternate EVE-OS root filesystem
4	CONFIG	5.0 MiB	Edge node identity & configuration
9	P3	~467 GiB	Persistent data (read-write)

To verify on your device:

sgdisk -p /dev/sda

Revert Boot to IMGB Partition

Step 1 — Clear Priority Flag from IMGA

sgdisk --attributes=2:clear:48 /dev/sda

Step 2 — Set Priority and Successful Flags on IMGB

sgdisk --attributes=3:set:48 /dev/sda
sgdisk --attributes=3:set:56 /dev/sda

Bit	Meaning
48	Priority — GRUB prefers this partition
56	Successful — partition is bootable

Step 3 — Reboot

reboot

Step 4 — Verify After Reboot

cat /run/eve.id      # should now show IMGB
cat /etc/eve-release # confirm the version

To Revert Back to IMGA

sgdisk --attributes=3:clear:48 /dev/sda
sgdisk --attributes=2:set:48 /dev/sda
sgdisk --attributes=2:set:56 /dev/sda
reboot

Notes

IMGA and IMGB are read-only squashfs filesystems — they cannot be modified while running.
The CONFIG and EFI partitions must be preserved — corrupting them requires a full reinstall.
These changes take effect on the next reboot only.
After an OTA update, EVE normally switches partitions automatically. This procedure is for manual intervention only.

ZEDEDA WiKi

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