So called ‘low cost’ developer boards (like BeagleBoard xM, PandaBoard, Snowball, MX53 Quick Start) do not have NAND flash on them so people are using SD/MMC cards as boot media and storage. So we, developers, went to shops and bought SD cards. Some got class4 ones cause budget was low already, some grabbed class10 ones hoping that they will be fast, other took class6.
I got some 4GB Transcend class10 ones. They worked, gave me 15MB/s on read and were fine. Until recently they started giving strange kernel output, MMC timeouts, I/O errors which resulted in filesystem going into read only mode. As I prefer to have working board then wondering how much time it will survive I trashed both cards. Good that I had some spare unknown 8GB microSD ones. But in last ~year I had to throw away 4 SD cards…
One of solution for it is moving rootfs to some more reliable storage. I did that with MX53 Quick Start — it has 320GB Serial-ATA harddrive connected. So for PandaBoards I could use 8-16GB thumb drives or USB connected hard drives. I had this in past when there was no mx53 hardware at my desk. But this means extra costs, additional cables, probably even another set of power cables…
Will have to check market for good reliable SD cards soon. 8-16GB ones so there will be space available for doing builds. Or will switch to old school NFS root which requires only 64MB cards — just to load bootloader, kernel, initrd. Other option is a network storage like NBD, AoE or iSCSI but this requires more configuration.