I suspect a silent hardware failure has occurred, which is going undetected by several probing tools. * This may be causing data corruption and the hardware is to be replaced ASAP.
The failure suspect comes from several different, random errors like programs segfaults, DMA / CRC errors, processes killed by kernel without explanation, etc..
Temporary replacement hardware will be ready to service for the 23th afternoon.
* List of probing tools used to check the hardware, with no positive reports:
- S.M.A.R.T. disks self probe