I use Jolla with /home/nemo mounted from 16gb sdcard, formatted as ext4, and it works perfectly.

Then I've bought 64gb sdcard (sony), created a Linux partition with cdfisk, formatted as ext4, and rsynced information from the old card to the new one.

Since that, some software, let's say Sailfish browser hungs from time to time.

It is possible to minimize it, the software, I guess, does i/o, and hungs at that time.

I've checked the speed of sdcard with hdparm and it's perfectly okay.

I've formatted it again, this time made a tar archive from the old one, and unpacked the tar archive to the new one. Again, sometimes it hungs.

I've tried to run vmstat, and see what's going on and may be there is a correlation between context switches that raise to 1500-2000 and that's when the application becomes unresponsive.

Of course Sailfish dialog appears, it asks what to do - wait or kill the application. Wait always helps, it just comes back soon. Sometimes in 15 seconds.