disk - Is there any way of detecting if a drive is a SSD?

Question

I'm getting ready to release a tool that is only effective with regular hard drives, not SSD (solid state drive). In fact, it shouldn't be used with SSD's because it will result in a lot of read/writes with no real effectiveness.

Anyone knows of a way of detecting if a given drive is solid-state?

Answer 1

Finally a reliable solution! Two of them, actually!

Check /sys/block/sdX/queue/rotational, where sdX is the drive name. If it's 0, you're dealing with an SSD, and 1 means plain old HDD.

I can't put my finger on the Linux version where it was introduced, but it's present in Ubuntu's Linux 3.2 and in vanilla Linux 3.6 and not present in vanilla 2.6.38. Oracle also backported it to their Unbreakable Enterprise kernel 5.5, which is based on 2.6.32.

There's also an ioctl to check if the drive is rotational since Linux 3.3, introduced by this commit. Using sysfs is usually more convenient, though.