{"id":37794,"date":"2022-12-01T16:45:45","date_gmt":"2022-12-01T21:45:45","guid":{"rendered":"https:\/\/mjtsai.com\/blog\/?p=37794"},"modified":"2022-12-02T15:48:46","modified_gmt":"2022-12-02T20:48:46","slug":"long-app-hangs-due-to-spotlight","status":"publish","type":"post","link":"https:\/\/mjtsai.com\/blog\/2022\/12\/01\/long-app-hangs-due-to-spotlight\/","title":{"rendered":"Long App Hangs Due to Spotlight"},"content":{"rendered":"

Whenever I mount a hard drive with lots of files, typically a clone drive, various other apps that deal with files often hang<\/a>. An individual hang can last for minutes to over half an hour. If the app is doing a long series of file operations, which would normally take fractions of a second, it can be unusable until some time after the drive has been unmounted. This happens even though the apps in question are not accessing files on the hard drive. The problem has been occurring since Monterey but has gotten a lot worse in Ventura. It got to the point where I didn’t want to do any backups during the day since my Mac could essentially become unusable for hours, even after pausing or aborting the backup.<\/p>\n\n

Sampling the hung apps shows that they are waiting (for an XPC process) to read or write Spotlight metadata. I don’t know exactly what’s going on, but it’s as if<\/em> the newly mounted drive generates lots of potential work for Spotlight to update its index. You would think that each volume would have its own work queue, but it seems like there’s a single queue so that operations for the slow hard drive, which are not time-sensitive, block high-priority operations for the internal SSD. Maybe this is exacerbated by the fact that my clone drives get ejected after the backup completes so that the Spotlight index is always way out of date.<\/p>\n\n

Once I traced the problem to Spotlight, the obvious workaround was to exclude those volumes from indexing. This is, in fact, effective, though it has some problems:<\/p>\n