Correct the macOS error: snap_metadata_val object (): invalid extentref_tree_oid (0x0)

Your macOS drive is a mess, the system seems to idle and the fan tends to panic more than reason? Your TimeMachine backup no longer ends?

You went to High Sierra and converted your disk to APFS?

Start in “Repair” mode (Command + “R” all the way through the boot phase), run the disk parser on your hard disk and it is likely that you get the following error:

snap_metadata_val object (oid <aléatoire>): invalid extentref_tree_oid (0x0)


Snapshot metadata tree is invalid

To repair that, follow this guide :

Restart your system normally and in a terminal prompt, list the snapshots created :

$ tmutil listlocalsnapshots / (dataless)

If the list shows a dataless snapshot like above, delete it:

$ tmutil deletelocalsnapshots 2018-03-20-112749
Deleted local snapshot '2018-03-20-112749'

and the problem is solved !


2 thoughts on “Correct the macOS error: snap_metadata_val object (): invalid extentref_tree_oid (0x0)

  1. I have this exact issue, but using tmutil to delete the dataless snapshots does not work permanently (new dataless snapshots are created at least once a week). Any idea how to permanently fix this? Thanks!

  2. Hi Nate,
    Do you have timemachine working fine ? It appears to clear localsnapshots and keep them away.
    I parallel, you must investigate what creates dateless snaps. I’m currently using latest beta and this problem did not occur for a while

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