Loud Disk Access after crash
I am on macOS 10.15.7 and after an app crashes and I get the crash report window, both my ThunderBay 4 (single 1+0) and ThunderBay 8 (two 1+0s) get loud with lots of disk access for about 10 seconds and are then quiet again.
I am a software developer so this is a common occurrence. Why do they do this?
My theory is when you have an unclean shutdown, at restart, macOS is repairing the volume. That would entail lots of small IO's. It would explain what you hear.
@softraid-support This is not at restart. For example, Opera crashed recently and an OS-generated window came up that said "Problem Report for Opera", with a crash report in it. After closing that window with either OK or Relauch buttons, the disks have lots of access. This happens regardless of which app crashes.
@softraid-support There are three volumes, each 16tb 1+0 (so 32tb of drives). One drive is indexed with Spotlight and contains lots of files. The other two are backups of each other and each contains a single encrypted sparse image file that is about 10tb (obviously containing lots of files within the sparse bundle). These sparse volumes are not indexed. It is hard to tell if all volumes are making this sound via read/write as the lights on the units do not flash when this is happening. It gradually gets quieter so it seems all drives start out doing r/w and it slow diminishes as each drive finishes over the course of a few seconds.
the crash could be triggering macOS to flush the cache on the drives, which would result in lots of tiny I/O's, and with noisier drives, be apparent to hearing. Your system is writing bunch of discontinuous writes, if on an APFS volume, even more so.
Thats my best guess here.