Question

On the emulator, I can unmount the SD card from the Settings.

I can then mount it on my OS, then unmount it normally.

I haven’t been able to figure out how to re-mount it then on the emulator (without rebooting it).

hints:

• the adb command remount is unrelated: it’s about /system
• the emulator command is unrelated: it’s only about starting the emulator
• mounting the SD card in two places of course messing everything up (I tried)

more:

• mount outputs the following:

  /dev/block//vold/179:0 /sdcard vfat rw,dirsync,nosuid,nodev,noexec,uid=1000,gid=1015,fmask=0702,dmask=0702,allow_utime=0020,codepage=cp437,iocharset=iso8859-1,shortname=mixed,utf8,errors=remount-ro 0 0

• trying to mount again from the shell after unmounting it, using the same options as above, gives a segfault

• no idea why the double slash in block//vold, I guess it’s just a typo

Answer 1

The developers guide suggests that this isn’t possible:

SD Card Emulation

You can create a disk image and then
load it to the emulator at startup, to
simulate the presence of a user’s SD
card in the device. To do this, you
can use the android tool to create a
new SD card image with a new AVD, or
you can use the mksdcard utility
included in the SDK.

The sections below describe how to
create an SD card disk image, how to
copy files to it, and how to load it
in the emulator at startup.

Note that you can only load disk image
at emulator startup. Similarly, you
can not remove a simulated SD card
from a running emulator. However, you
can browse, send files to, and
copy/remove files from a simulated SD
card either with adb or the emulator.

The emulator supports emulated SDHC
cards, so you can create an SD card
image of any size up to 128 gigabytes.

While Android will unmount the SD card, the emulator process keeps the backing file open.

$ ls -go /proc/`pidof emulator`/fd | grep sdcard.img
lrwx------ 1 64 2010-05-13 01:50 10 -> /home/x/.android/avd/WithSD.avd/sdcard.img

Someone more familiar with QEMU may be able to provide further insight but, if I were you, I would just try to use NFS to solve this problem.