Yes, this is expected behaviour. L2ARC does not invalidate previously written data on cache devices even if they are removed from the pool.
You do not need to worry though, the outdated L2ARC data will NOT be served, as their checksum, DVA properties, and birth transaction will differ from the data present in the disks of the pool. On Tue, Oct 20, 2020, 6:03 PM <adam.blaszczykow...@gmail.com> wrote: > Hello, > I have noticed unusual behaviour with Persistent L2ARC . I will try to > describe how to reproduce this problem. > All tests are performed on zfs-2.0.0-rc1_71_g51de0fc. I am using Virtual > Machine on ESXi 6.7 server. > > Test scenario: > 1. ZFS pool created with L2ARC that has about 8,4 GB of data on L2arc disk > 2. Disconnecting VM disk with L2ARC from Virtual Machine > 3. Deleting some data from the zpool with disconnected L2ARC disk > - zpool iostat command shows that some of cached data also has been > removed from disconnected L2ARC disk > 4. Reconnecting VM disk with L2ARC disk to Virtual Machine and rebooting > system > 5. Adding new data to the zpool - new data are cached in L2ARC disk > 6. Deleting all data from zpool > 7. L2arc disk still has some data, even if there is no data on zpool > 8. Rebooting system > 9. After reboot the same situation, zpool is empty but L2ARC disk still > has some data > > I am expecting that deleting all data from zpool also removes data from > L2ARC cache. > Is it normal behaviour of Persistent L2ARC? > > Thank you > *openzfs <https://openzfs.topicbox.com/latest>* / openzfs-developer / see > discussions <https://openzfs.topicbox.com/groups/developer> + participants > <https://openzfs.topicbox.com/groups/developer/members> + delivery options > <https://openzfs.topicbox.com/groups/developer/subscription> Permalink > <https://openzfs.topicbox.com/groups/developer/T77c79c75ab05a912-Me6344594a06ca2007e812e93> > ------------------------------------------ openzfs: openzfs-developer Permalink: https://openzfs.topicbox.com/groups/developer/T77c79c75ab05a912-Mb34a9323a370dcef95a2d53f Delivery options: https://openzfs.topicbox.com/groups/developer/subscription
