Re: boot errors since upgrading to 12-current

> On 14 Aug 2018, at 22:37, tech-lists <tech-lists_at_zyxst.net> wrote:
> 
> Hello,
> 
> context: amd64, FreeBSD 12.0-ALPHA1 #0 r337682, ZFS. The system is *not* root-on-zfs. It boots to an SSD. The three disks indicated below are spinning rust.
> 
> 	NAME        STATE     READ WRITE CKSUM
> 	storage     ONLINE       0     0     0
> 	  raidz1-0  ONLINE       0     0     0
> 	    ada1    ONLINE       0     0     0
> 	    ada2    ONLINE       0     0     0
> 	    ada3    ONLINE       0     0     0
> 
> This machine was running 11.2 up until about a month ago.
> 
> Recently I've seen this flash up on the screen before getting to the beastie screen:
> 
> BIOS drive C: is disk0
> BIOS drive D: is disk1
> BIOS drive E: is disk2
> BIOS drive F: is disk3
> BIOS drive G: is disk4
> BIOS drive H: is disk5
> BIOS drive I: is disk6
> BIOS drive J: is disk7
> 
> [the above is normal and has always has been seen on every boot]
> 
> read 1 from 0 to 0xcbdb1330, error: 0x31
> read 1 from 0 to 0xcbdb1330, error: 0x31
> read 1 from 0 to 0xcbdb1330, error: 0x31
> read 1 from 0 to 0xcbdb1330, error: 0x31
> read 1 from 0 to 0xcbdb1330, error: 0x31
> read 1 from 0 to 0xcbdb1330, error: 0x31
> read 1 from 0 to 0xcbdb1330, error: 0x31
> read 1 from 0 to 0xcbdb1330, error: 0x31
> 
> the above has been happening since upgrading to -current a month ago
> 
> ZFS: i/o error - all block copies unavailable
> ZFS: can't read MOS of pool storage
> 
> the above is alarming and has been happening for the past couple of days, since upgrading to r337682 on the 12th August.
> 
> The beastie screen then loads and it boots normally.
> 
> Should I be concerned? Is the output indicative of a problem?
> 

Not immediately and yes. In BIOS loader, we do all disk IO with INT13 and the error 0x31 is often hinting about missing media or some other controller related error. Could you paste the output from loader lsdev -v output?

The drive list appears as an result of probing the disks in biosdisk.c. The read errors are from attempt to read 1 sector from sector 0 (that is, to read the partition table from the disk). Why this does end with error, would be interesting to know, unfortunately that error does not tell us which disk was probed.

Since you are getting errors from data pool ‘storage’, it does not affect the boot. Why the pool storage is unreadable - it likely has to do about the errors above, but can not tell for sure based on the data presented here…. 

rgds,
toomas