eMMC as backup on MAX units

tedquade

I have wandered if it is possible to install a backup running system on the eMMC drive that I expect resides on MAX units. I have a 4100MAX and 6100MAX I would like to set up this way. I would normally leave the eMMC idle and run the device on the MAX drive.

Ideas and thoughts.

Ted

SteveITS

@tedquade Assuming it’s possible I would just install at that point? Then you can restore your then-current config file.

Gertjan

@tedquade

I've a 4100 MAX.
Never opened it, but saw some images and video's about it.
There is only 'one' M2 slot, probably occupied by my SSD. The non MAX version will have an emmc in that place.

I saw the 6100 has 2, or even 3 slots, and that one can be expanded with extra drives easily.

I hope to be wrong of course, as if I do have an empty slot, I will open it up, as my warranty situation shows the green light now (its expired).
A somewhat scary Youtube video I saw recently (I'll look it up) told me what the ZFS file system does with SSD drive(s). It will eat any emmc drive for breakfast, that's (for me) known knowledge since ZFS exists. But my SSD will be dinner for sure.

An extra drive in my pfSense will be great for an extra fast and easily accessible backup system.
All it needs is a new paper tag on box that states : "remember to check /etc/fstab" where I have to place a line so the device gets mounted at boot. As this file can get modified by pfSense (not sure) and will get modified when I re install, it's just one extra admin task to take care of.
Also : another text "Be careful when re installing" as now the installer will list the two drives as potential destinations for a pfSense install : the selected drive will be wiped clean before installing.
If I don't mess up the new install, and did use the correct file path (/cf./conf) on my backup drive for the backed up config.xml, the installer would find it this file when re installing and my pfSense would be set up correctly right from the start without using a backup USB or remote backup file or even use abc.

edit : Found this https://docs.netgate.com/pfsense/en/latest/troubleshooting/disk-lifetime.html#checking-disk-health-lifetime.
At first, I thought it wasn't applicable for me, as my 4100 has an SSD, not the emmc.
I was wrong.

I installed the tools :

pkg install -y mmc-utils; rehash

and then :

mmc extcsd read /dev/mmcsd0rpmb

which I copied verbatim. because a ls -al /dev/ tells me I have "emm" devices (partitions) :

So, wait ... I have both an SSD 115 G and a "16 G" emmc drive ?
If I understand "gpart list" well enough, I have ....

Ok : go for it :

and 0x01 means : barely used.

Question : can I use this mmcd0 drive and or partitions (boot0/1/p1/2/3/4/rpmb) ?
Or, the thread subject says it all :

eMMC as backup on MAX units

?

SteveITS

@tedquade
https://docs.netgate.com/pfsense/en/latest/troubleshooting/multiple-disks.html

Of course you could also install another SSD.

tedquade

@SteveITS Thanks for the pointer to the docs. Looks like this approach may be fraught with problems. I'll leave well enough alone.

Ted

stephenw10

Yes, you can install to eMMC and SSD and boot from either but there are caveats!

Firstly you can easily create a conflict between the two installs. For example you can't have two ZFS pools named 'pfSense'. So if you have both installed as ZFS one should be set a different pool name. The same can be true if both are UFS, you can end up mounting root from the wrong drive. So when I have done this the easiest way to ensure that doesn't happen is to install one drive as ZFS and the other as UFS.

On the 4100/6100 it is difficult to add a UEFI boot entry for the eMMC. The system will auto-add one if you clear the list then try to boot without an NVMe drive present. You can then add the NVMe and install to it and reorder the boot list as required.

Gertjan

@stephenw10

And using it as a simple data drive ? As I just discovered (thanks, @tedquade ) that my 4100 MAX has an emmc installed also.

The doc told me to zero/wipe it out. Reformat if using the clasic EXT4 or way more dumb : the msdos format, and store files on it. Just ones in a while, its emmc, I won't ask it to work for me ^^

How to mount it ?

stephenw10

I'm talking about having two separate installs with one as a backup.

Using a separate drive in an existing install is not supported. You need some custom scripting to handle mounting the drive at boot etc.