On Mon, Jun 07, 2021 at 10:27:20AM +0000, Martin Wilck wrote: > Most importantly, this was about LVM2 scanning of physical volumes. The > number of udev workers has very little influence on PV scanning, > because the udev rules only activate systemd service. The actual > scanning takes place in lvm2-pvscan@.service. And unlike udev, there's > no limit for the number of instances of a given systemd service > template that can run at any given time.
Excessive device scanning has been the historical problem in this area, but Heming mentioned dev_cache_scan() specifically as a problem. That was surprising to me since it doesn't scan/read devices, it just creates a list of device names on the system (either readdir in /dev or udev listing.) If there are still problems with excessive scannning/reading, we'll need some more diagnosis of what's happening, there could be some cases we've missed. Dave _______________________________________________ linux-lvm mailing list linux-lvm@redhat.com https://listman.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
