On two occasions I have experienced two of four slices in a four disk array going offline in the wee hours of the morning while doing heavy batch processing and concurrently running smart short tests on the drives via crontab. My crontab consecutively starts the short test on all drives, and since it backgrounds them, they all are running concurrently. I suspect that the linux implementation of software raid is not able to handle the heavy disk IO while all the drives are also doing their smart test. The first time this happened the first two stripes went offline, and the second time the other two went offline. Luckily on both occasions I was able to reassemble the array (eight hour process) and did not lose any data. This email is more of an FYI, or looking for verification that what I experienced was probably caused by the events as I outlined them above. Thoughts? Linux 4.20.x kernel line on SMP E5440 server supermicro X7DAE motherboard 32GB of ECC RAM
