Why is my Disk Image boot so slow?

A few things to consider:

The first time you boot any of these disk images, the computer may not be correctly configured for your network. In this situation, the system will boot VERY slowly as various RPC calls fail. It can take up to 5 minutes for some of these systems to boot when they aren’t properly set up.

Be patient. Once the system finally finishes booting, follow the network setup steps listed in the README files to fix the network configuration. It may take a few reboots to get everything working correctly. Once properly configured, most of these machines will boot in 1 to 2 minutes.

If you believe everything is set up correctly, the next thing to check is the SD card you're using. While most brands of SD cards work fine, occasionally, you may encounter a defective one (even if it’s brand new). For example, I once had a new SanDisk card that took over 6 minutes to boot an image. I assumed the card was defective, possibly mapping out damaged memory areas. This issue is invisible to the host but can significantly slow down the card's performance. I discarded the faulty card, and all the others I bought at the same time worked fine.

Finally, a useful tip when changing images on a card is to reformat the card before copying the disk image onto it. This increases the likelihood that all parts of the image will be located on contiguous bytes on the card, speeding up read times. The Zulu debug file on the card will indicate if the image is contiguous, but I haven’t found any app that can guarantee it when the image is written to the card.