Android 模拟器快照标志不起作用

Question

Android Emulator snapshot flag is not working as expected. I created a new avd with name Mydevice using

tools/bin/avdmanager create avd --force --name Mydevice --abi google_apis/x86 --package 'system-images;android-29;google_apis;x86' --device "Nexus 6P" &

Now I run this avd using

sudo emulator/emulator -avd Mydevice  -no-window -port 5554

After emulator is booted successfully, I take a snapshot using

adb -s emulator-5554 emu avd snapshot save Snap1

which successfully creates the snapshot.

Now I stop my running emulator using

adb -s emulator-5554 emu kill

Now I again run the emulator using -read-only flag and using the saved snapshot using

sudo emulator/emulator -avd Mydevice -read-only -no-window -port 5554 -snapshot ~/.android/avd/Mydevice.avd/snapshots/Snap1

but it seems like -snapshot is getting ignored as emulator is still taking same time as earlier to boot.

I also tried removing the read only flag but that did not helped.

Answer 1

The argument to -snapshot is a snapshot tag name, not a path.

First, list the snapshots like this:

emulator/emulator -avd mydevice -snapshot-list

which will produce output like this (so far I haven't figured out how to list snapshots without actually starting the emulator as well, but for now just shut down the emulator after running this command):

ID        TAG                 VM SIZE                DATE       VM CLOCK
--        snap_2020-12-03_13-31-29    90M 2020-12-03 13:31:29   01:11:57.073
--        default_boot            68M 2020-12-03 14:15:33   00:02:08.928

Then, start the emulator using one of the values in the "TAG" column eg:

emulator/emulator -avd mydevice -snapshot snap_2020-12-03_13-31-29

For Android Studio, the "advanced settings" for devices in the AVD Manager also have a drop-down for selecting a snapshot to start the device with.

As a side note, I've found that starting an emulator image from a snapshot drastically improves its performance, at least on my Linux box. With the snapshot flag, the emulator's disk writes are normal -- without it, for some reason the emulator is essentially constantly writing to disk, slowing everything to a crawl. I honestly don't know why that is.