SD Card "hot swap"

[AALLeeXX]

Hello everybody,

My setup is
Host iMac OS X 10.11.4
Guest Ubuntu 14.04 TLS
Virtual box 5.0.16

I can access a SD Card contents when plugged in the iMac reader after I created a vmdk disk connected to it and finally attach this file to a virtual hard drive. It's ok.

However, once this SD Card (A) is connected, I cannot replace it by another SD card (B) when the VM is running. I currently have to shut down the VM, change the settings to attach the B vmdk file to another virtual hard drive and restart my VM.

Is there a hot swap method that allows to simply change SD cards anytime when a VM is running ?

Thank you for any tips and help,
Alexandre

[AALLeeXX]

Hi,

It seems like I'm alone to use the built in card reader of the Mac, is it so
How are you doing to play with your SD Cards ? Any simple solution ?

Thanks,

Alexandre

[socratis]

Have you tried to use shared folders? It's an order of magnitude (if not more) easier compared to raw VMDK access.

[AALLeeXX]

Hi,

Yes I do use the share folder, but I did not use it to copy my img files on OS X then from OS X to dump the img to the SD card. Is it what you meant ?

Thx,
Alex

[socratis]

I'm not quite sure what that means. Can you be a little bit more specific? Step-by-step instructions?

[AALLeeXX]

Well, sorry, was not sure either about your idea.

I imagine your proposal is :
- transfer the file from Virtual box (linux) to OS X
- within OS X copy the file to the SD card.
- then if I need to copy something else to *another* SD card, I change the SD card and proceed with the copy under OS X.

Is it correct ?

My wish would be to do all these operations within the Virtual box simulated machine - which I cannot do.

[socratis]

Close... I'm not sure how the SD card shows up in OSX, since I've never seen that one.
- What kind of a Mac do you have? EXACTLY!
- How does the SD card show in Finder?
- If you navigate to "/Volumes" does it show? How?
- If it does show (for example, "/Volumes/SD Card"), share that folder.

[AALLeeXX]

How an SD card shows in OSX ? I think it depends on its contents and OS X ability to read the partitions.
Also depends on the tool. For example one with linux paritions only (ext3fs) the card is simply not visible in the finder.

My mac is an iMac 27" late 2013
In the finder, it depends on the contents:
- FAT32 card will appear in the list of devices with a small eject icon to umount it.
- A mixed contents (FAT and extfs3) card will show in finder only readable contents for OS X, ie FAT in this case. ext3 contents remains hidden.

Diskutil list can report all partitions and their types (in cmd line only, GUI version shows only the FAT)
/Volumes is like diskutil GUI, only FAT is visible. The visible partition appears with its name. Unreadable one are no shown

Let say I share this folder, if I change the card, the subfolder name will change, thus swap will not be possible or will crash the VM. I will try sharing the /Volumes folder in case...

[AALLeeXX]

Well, /Volumes in the VM guest does not show any folderrelated to the card - which is quite logic since the SD is mounted in the VM and not in OS X...

Thanks for the idea - unfortunately unsuccessful.

[AALLeeXX]

Sorry, I made a mistake above. I kept the SDCard virtual disk attached to the VM... this made the guest OS to mount the SD card through the VM. Thus it was not available any more in the host OS (OSX).

I tried then without the SD card virtual disk in the VM. The SD card remained mounted in OSX and was visible in /Volumes. Since /Volumes was set as a shared drive in the VM, I could access it from the guest OS in the VM (as root).
Nevertheless, I bumped onto OSX limitations: in /Volumes appear only OSX readable partitions. With that I don't know how to dump an img file to the SD card.

Much better since this allows to swap the SD cards easily, without managing virtual drive for them.
Still remain the limit of the 'block' access for, eg, img dump...