What about powered SSDs that contain files that are rarely read?
My desktop computer is generally powered except when there is a power failure, but among the million+ files on its SSD there are certainly some that I do not read or write for years.
Does the SSD controller automatically look for used blocks that need to have their charge refreshed and do so, or do I need to periodically do something like "find / -type f -print0 | xargs -0 cat > /dev/null" to make sure every file gets read occasionally?
no, the firmware does any maintenance. good firmware should do gradual scrub whenever it's idle. unfortunately, there's no real way to know whether the firmware is good, or doing anything.
I wonder if there's some easy way to measure power consumed by a device - to detect whether it's doing housekeeping.
Honestly this is one of my favorite things about ZFS. I know that a disk scan is performed every week/month (whatever schedule). And I also know that it has verified the contents of each block. It is very reassuring in that way.
You've validated that the scrub is actually running, right? I know that the lack of a default schedule for ZFS scrubs caused Linus Media Group to lose a bunch of archived videos to bitrot.
I also need an answer to this.
It's fine. But the whole drive can turn to dust at any time, of course.
You should absolutely be doing a full block read of your disk, dd if=/dev/disk of=/dev/null every couple weeks
pretty accurate username
Amusing profile too. For some reason he calls us here on HN a "congress".
pointless to do it by the default 512b block size though.