OMV Backup Plugin backing up entire SD, not just OS partition.

  • So, i'm using the option for the OS partition only, but the plugin is writing a file equivalent to the side of the SD card ( 64GB!!!).

    I suspect this could simply be how the card is being burned with the image?

    I'm using this tutorial here for creating the image. (Armbian Buster Server on RockPro64); used Etcher to burn the image.

    Off-Grid Home Server Project:

    ROCKPro64 4GB (Rockchip RK3399 Hexa-Core)

    OMV 5.5.11 on Armbian Buster Server

    SD boot | 128GB SSD Docker Storage | 2x 1TB SSD RAID1 Storage

  • i'm using the option for the OS partition only,

    What is the name of the option you are using?

    but the plugin is writing a file equivalent to the side of the SD card ( 64GB!!!).

    And the backup file's final size would never be the size of the SD card since it is gzip'd

    omv 5.5.17-3 usul | 64 bit | 5.4 proxmox kernel | omvextrasorg 5.4.2
    omv-extras.org plugins source code and issue tracker - github


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  • I'm not in front of my system right now so I'm going on memory as it looks like OMV5 added other backup options; I recall using DD which I thought specified just the OS/Boot partition.

    The backup file was indeed 64gb though. I can screenshot later. Again, is it possible that the Armbian/OMV install expanded itself out onto the entire SD card...I read something similar to this on a Pi forum recently.

    Off-Grid Home Server Project:

    ROCKPro64 4GB (Rockchip RK3399 Hexa-Core)

    OMV 5.5.11 on Armbian Buster Server

    SD boot | 128GB SSD Docker Storage | 2x 1TB SSD RAID1 Storage

  • I recall using DD which I thought specified just the OS/Boot partition.

    Unless you shrink the OS partition, the OS and boot partition take up the entire SD card. Therefore, the backup plugin is doing the correct thing.


    The backup file was indeed 64gb though. I can screenshot later

    If gzip couldn't compress the image at all, that would be amazing.


    Again, is it possible that the Armbian/OMV install expanded itself out onto the entire SD card

    It definitely does expand the OS partition to fill the rest of the card. Armbian and Raspberry Pi OS both do this.

    omv 5.5.17-3 usul | 64 bit | 5.4 proxmox kernel | omvextrasorg 5.4.2
    omv-extras.org plugins source code and issue tracker - github


    Please read this before posting a question.
    Please don't PM for support... Too many PMs!

  • Unless you shrink the OS partition, the OS and boot partition take up the entire SD card. Therefore, the backup plugin is doing the correct thing.

    Ah Ha! So that's extremely valuable to know. I don't really see any of this in the help docs unless i've missed them. Is there a best practice for this (aside from / rather than cloning the SD? Specifically related to shrinking the partitions?


    Also, I had planned to NAND-SATA-INSTALL my SD install to my eMMC module but will that even work now if the eMMC is smaller than the SD?

    Off-Grid Home Server Project:

    ROCKPro64 4GB (Rockchip RK3399 Hexa-Core)

    OMV 5.5.11 on Armbian Buster Server

    SD boot | 128GB SSD Docker Storage | 2x 1TB SSD RAID1 Storage

  • I don't really see any of this in the help docs unless i've missed them.

    What help docs? The screen literally says it is expanding the OS partition when it boots the first time. I'm sure it is documented on the Armbian site and omv install guides.

    Is there a best practice for this (aside from / rather than cloning the SD?

    The two dd options are the only ones that backup blank space. fsarchiver and rsync just backup files. They aren't as easy to restore though (can't just write image to sd card). The best option is still to take the sd card out and clone it with clonezilla.

    Specifically related to shrinking the partitions?

    Shrinking? Boot gparted-live on the system you wrote the card with and shrink the partition. Easy.


    Also, I had planned to NAND-SATA-INSTALL my SD install to my eMMC module but will that even work now if the eMMC is smaller than the SD?

    Why? What are you hoping to gain? I've never used the nand-sata-install.

    omv 5.5.17-3 usul | 64 bit | 5.4 proxmox kernel | omvextrasorg 5.4.2
    omv-extras.org plugins source code and issue tracker - github


    Please read this before posting a question.
    Please don't PM for support... Too many PMs!

  • All very very helpful, thank you.


    Regarding pushing the install to the eMMC Module:

    • I'd like to have my one SD card slot available
    • I may wrongly be under the impression of a better lifespan for the eMMC vs SD.

    Also, I'm wishing I had known in advance about the OS expansion since i'll only be able to clone to a card of equal size moving forward (barring the use of Gparted).

    Off-Grid Home Server Project:

    ROCKPro64 4GB (Rockchip RK3399 Hexa-Core)

    OMV 5.5.11 on Armbian Buster Server

    SD boot | 128GB SSD Docker Storage | 2x 1TB SSD RAID1 Storage

  • I'd like to have my one SD card slot available

    Probably easier to just by a usb card reader if you need an SD card on an arm board.


    I may wrongly be under the impression of a better lifespan for the eMMC vs SD.

    It does last longer but is also a lot more expensive. I have had the same SD card on some of my systems for a couple of years. For the cost difference, you could just buy 3 SD cards and clone one to the others. If one started acting weird, switch to a new one.


    Also, I'm wishing I had known in advance about the OS expansion since i'll only be able to clone to a card of equal size moving forward.

    Not true. With rsync or fsarchiver, you could use any size as long as what was backed up wasn't larger than the new SD card. The best way to restore is write the armbian image to the new sd card and then restore the backup (just files) over that. It doesn't care what size the filesystem is.

    omv 5.5.17-3 usul | 64 bit | 5.4 proxmox kernel | omvextrasorg 5.4.2
    omv-extras.org plugins source code and issue tracker - github


    Please read this before posting a question.
    Please don't PM for support... Too many PMs!

  • You are amazing. This thread answers so many questions I've had since I made the move from OMV4 to 5 last week. Thank you so very much.

    Off-Grid Home Server Project:

    ROCKPro64 4GB (Rockchip RK3399 Hexa-Core)

    OMV 5.5.11 on Armbian Buster Server

    SD boot | 128GB SSD Docker Storage | 2x 1TB SSD RAID1 Storage

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