@shabinet OK so given your logs are full of the S.M.A.R.T probe logging that would be good to address initially. Mostly harmless but easy enough to address. If you take a look at the docs section on Disk Custom S.M.A.R.T Options you will see the example there addresses the Sandisk Extreme which, for the time being, exhibits the same behaviour from smartctl ‘under the hood’ as you are seeing with this ‘Ultra’ model. If you follow that example and add a “-d sat” as custom option to your SanDisk_Ultra it should quiet your logs down some. Then we can more easily see any other activity. This option, on that model, won’t unfortunately grant access to smart info (as it does with the Extreme) as I don’t believe it’s actually available with Ultra model but it will at least calm the probe logging down.
Which means you are essentially on the latest available code anyway so we don’t ‘just yet’ have a critical issue on the code update front. We just need to get you over the ‘holiday period’ as this issue may well be related to a ‘backend’ issue that is more in the realm of @suman. Re the announcement post for 3.9.1:
Lets just see if there’s anything obvious to address or any more info once those smart log probe entries are appeased.
Hope that helps.