Dne 11. 04. 19 v 12:01 Eric Ren napsal(a):
Hi,

Another error message is:

"Failed to suspend thin snapshot origin ..."

which is in _lv_create_an_lv():

```
7829         } else if (lv_is_thin_volume(lv)) {
7830                 /* For snapshot, suspend active thin origin first */
...

is active */
7843                         if (!update_pool_lv(pool_lv, 0)) {
7844                                 stack;
7845                                 goto revert_new_lv;
7846                         }
```

I don't understand why we need to suspend_lv_origin() and resume_lv_origin() in line?

And, what reasons might cause this errors?


Hi

When you take any snapshot (thin or thick) the origin LV is suspend with fsfreeze operation - so the snapshot is takes with filesystem in 'consistent' state.

Otherwise without this - you may end-up with fs junk in your device - as the metadata of the filesystem might have stated in page-cache - and no fsck utility would be able to figure out what should be correct state of 'fs' without losing various amount of data in this operation.


Regards

Zdenek

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