Change in /data partition size between installer‑image v3.14 and v3.66 on MultiPlus‑II GX

Modifications
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1

Hi, I have noticed a change in the partition layout on our MultiPlus‑II GX devices, and I’d like to get confirmation from Victron or the community.

On our older MultiPlus‑II GX units (Venus‑OS installer v3.14, 20240124050751):

root@nanopi:~# lsblk
NAME         MAJ:MIN RM  SIZE RO TYPE MOUNTPOINTS
mmcblk1      179:0    0  7.3G  0 disk
|-mmcblk1p1  179:1    0    8M  0 part
|-mmcblk1p2  179:2    0    2G  0 part
|-mmcblk1p3  179:3    0    2G  0 part /
|-mmcblk1p4  179:4    0    1K  0 part
`-mmcblk1p5  179:5    0  3.3G  0 part /data
mmcblk1boot0 179:8    0    4M  1 disk
mmcblk1boot1 179:16   0    4M  1 disk

On a newer MultiPlus‑II GX (Venus‑OS installer v3.66, 20250915121157):

root@nanopi:~# lsblk
NAME         MAJ:MIN RM  SIZE RO TYPE MOUNTPOINTS
mmcblk1      179:0    0  7.3G  0 disk
├─mmcblk1p1  179:1    0    8M  0 part
├─mmcblk1p2  179:2    0  3.1G  0 part
├─mmcblk1p3  179:3    0  3.1G  0 part /
├─mmcblk1p4  179:4    0    1K  0 part
└─mmcblk1p5  179:5    0  1.2G  0 part /data
mmcblk1boot0 179:8    0    4M  1 disk
mmcblk1boot1 179:16   0    4M  1 disk

The total eMMC size (7.3 GB) has not changed; only the partitioning has shifted, going from 3.3 GB /data to 1.2 GB /data, while both root partitions were increased in size but the actual root filesystem remains unchanged.

Is this layout change intentional and expected behavior starting with a certain installer‑image generation?
Can you point me to the exact release / installer‑version where this change was introduced?

Currently, we use the /data directory to store:

  • Custom modifications to the Venus OS Large image
  • A small VPN client for remote access
  • The Node‑RED flow and its required Node modules

1.2 GB is barely enough for our current use‑case, but we are lacking space apply updates to our modifications.

Is there a recommendation on where to persist these kinds of modifications? Or is there any way to increase the data partition again?

Thanks in advance!

2

Yes, that is intentional. Since the installer version v3.66 the data partition size is kept the same for the 4GB and 8GB flash. The reason to do this is that the large image is getting quite full. You are rather exceptional to use such an amount of the data partition, for offline logging purposes an external storage is typically used.

Assuming you install a prebuild tarball or something, I would have a look at what these node-modules are installing, typically they don’t care about space, so look for:

  • dependency only need for installing / testing
  • docs / images / test scripts etc which aren’t needed on the target
  • prebuild binaries for completely different architectures

If you install binaries, don’t forget to strip them.

3

@jeroen Thanks for your fast answer and explanation.

Yes, we definitely have some room to optimize our package and the update process.
We were just very surprised to see the change without any mention in the release notes.

We have >100 devices deployed that were set up with installer 3.14. The newer devices will likely be set up with 3.66 or newer.

Do you have any strategy planned to handle the different partition schemas (varying data and root partition sizes)?
What is Victron’s plan for ensuring compatibility across devices with different partition layouts in future Venus OS releases? I assume a software update will not change the partitioning or will it?

Since you mentioned that the large image is getting full, do you plan to increase the root file system?