How can I debug this?

I have an Ubuntu 18 installation that goes years between total freezes of the computer, but it locks up each time within 20 minutes or so of trying to copy or clone a partition between two 6TB hard drives on the same external 2-disk SCSI dock. It suddenly becomes unresponsive to input by keyboard, mouse, ping or ssh. I've now seen this with attempts using dd, pv, partclone (via clonezilla) and rsync.

I don't see anything obvious in the system log, but don't really know what to look for. I don't have redundant hardware so will be buying replacement parts and trying them. Could someone advise me on what is most likely to need replacing?

The source drive? The target drive? The SCSI dock? The cabling? The motherboard? Is an update to Ubuntu 20 a likely fix?

How can I gather more information to debug this? Thanks!

  • One thing I can think is that one drive, particularly the source, is failing. Copy can start OK, but gets hung up when multiple read attempts are needed for each sector. Check disk status,e.g., S.M.A.R.T. stats. However, I also had a similar issue, traced to an external HDD with marginal power supply (perhaps deteriorating electrolytic caps?). Switching to another wall wart fixed it. Jun 12 at 2:00


You must log in to answer this question.

Browse other questions tagged .