After rebooting my cache is gone... no more data and saying "Unmountable: No file system"

What can I do?

knowlage-diagnostics-20190212-1943.zip

Edited February 13, 20197 yr by Jaster

Was this the config before rebooting, i.e., is cache5 supposed to be empty, also were there any recent changes to the pool, like any removed device?

Feb 12 19:41:21 Knowlage emhttpd: import 30 cache device: (sdp) Crucial_CT256M550SSD1_14110C0ABBC5
Feb 12 19:41:21 Knowlage emhttpd: import 31 cache device: (sdd) Samsung_SSD_840_EVO_120GB_S1D5NSBF356565L
Feb 12 19:41:21 Knowlage emhttpd: import 32 cache device: (sdq) Samsung_SSD_840_PRO_Series_S12RNEAD237385F
Feb 12 19:41:21 Knowlage emhttpd: import 33 cache device: (sdh) Samsung_SSD_850_PRO_256GB_S251NXAG707229V
Feb 12 19:41:21 Knowlage emhttpd: import 34 cache device: no device
Feb 12 19:41:21 Knowlage emhttpd: import 35 cache device: (sdn) Samsung_SSD_860_EVO_500GB_S3Z2NB0K928070H

The pool status is kind of strange, because all devices are present but also there's a misplaced device:

Feb 12 19:41:26 Knowlage emhttpd: cache uuid: 4e8aad16-d250-4b85-8232-bb5ce9b6f8e6
Feb 12 19:41:26 Knowlage emhttpd: cache TotDevices: 5
Feb 12 19:41:26 Knowlage emhttpd: cache NumDevices: 5
Feb 12 19:41:26 Knowlage emhttpd: cache NumFound: 5
Feb 12 19:41:26 Knowlage emhttpd: cache NumMissing: 0
Feb 12 19:41:26 Knowlage emhttpd: cache NumMisplaced: 1
Feb 12 19:41:26 Knowlage emhttpd: cache NumExtra: 0
Feb 12 19:41:26 Knowlage emhttpd: cache LuksState: 0

 

Don't remember seeing this before, below is the reason why it's not mounting, but not really sure what it means:

Feb 12 19:41:26 Knowlage kernel: BTRFS error (device sdp1): super_num_devices 5 mismatch with num_devices 5 found here

 

 

What happened: I was tinkering with the server and booted while one cache disk was unmounted. The cache started a rebuild (Raid5).

After it completed I shutdown (graceful), reattached the missing drive and booted up.

What you see is the result.

You could try updating to latest v6.7-rc, newer kernel might help, if it doesn't this is likely your best bet:

https://forums.unraid.net/topic/46802-faq-for-unraid-v6/?do=findComment&comment=543490

 

I just rebuild the cache and restored most stuff from my backup. I only struggle with restoring the VM configuration. I opened a Thread for that, hoping someone can help.