K3A

All of a sudden my Mac Mini froze and all I was able to do was to move the mouse cursor with spinning beach ball. I tried restarting, but the same thing happened a few minutes after booting. I figured out it was an SSD disk problem but decided to describe it in more details here.

Booting into recovery didn’t work either. The same thing happened a few minutes after booting. Single-user boot was better but then some binaries were killed with code 9 and if I remember correctly it also froze once.

I was suspecting SSD disk but I wanted to find some evidence so I inspected logs. I wasn’t able to find much information online so I decided to sum up some parts of the messages seen in the syslog here. Maybe it will help others.

cs_invalid_page final status devnode … Media is not present. Inalidate IOType. Vendor 0xffff is not valid.

I was able to boot to Ubuntu via a bootable USB disk with EFI version of GRUB and it was possible to use dd to back up every partition to files on an external USB3 drive this way:

dd if=/dev/sda1 of=/mnt/external/mac1.img bs=128k

/dev/sda1 – input partition we want to back up
/mnt/external/mac1.img – target file where to save the whole partition
128K block size

You can later mount such an image in your Mac with this command (Mac Terminal, working in Mac Recovery too):

hdiutil attach /Volumes/External/mac1.img

After taking SSD drive from the Mac and connecting it to another linux computer, mounting read-only, I discovered the problem. Reading files and browse partitions worked perfectly fine. But after writing some amount of data, the disk lost connection (shut down itself). It was OCZ Vertex 4 256GB 2.5″.

This time it was possible to back up data but if you are using SSD as well I strongly recommend you to do regular backups, for example using a tool like CrashPlan (free version allows you to use your other computers as targets for backup files). Because once SSD decides to stop reading your data, you have near-zero chance of getting your data back out of those memory chips.