I’ve been messing around with this one old array that has a slew of problems for some time now.
One thing I just figured out today, if you have an MSA20 and even though all the drives have a green light and are NOT marked as failed, the drives still can be in very bad shape.
Example: I have 5 X 250GB SATA drives, and EACH of the 5 drives had failed. The MSA20 said the drives were good, however multiple I/O errors were showing up on the kernel logs on a CentOS 5 install. Taking the drives out and testing them on a different system and NOT using the MSA20 shows that the drives are physically dead. Furthermore, popped in some random 500GB SATA drive I had sitting around in to the MSA20, and now the MSA20 works beautifully!