# System hangs on reboot [ZFS]



## jcoldwell (Oct 22, 2011)

Hello Forum,

My Problem: my server wouldn't come back up after a reboot. It is a 8.2-RELEASE system, running a two-disk ZFS mirror setup. It is a dedicated box in a remote datacenter. I can boot up some linux-based rescue system.

The way I installed FreeBSD on it was with mfsbsd, the zpool was created as such:


```
set poolname="z0"
set dev1="ad4"
set dev2="ad6"
set swapsize="4G"
set zfssize="300G"
gpart delete -i 1 ${dev1}
gpart delete -i 1 ${dev2}
gpart destroy ${dev1}
gpart destroy ${dev2}
gpart create -s gpt ${dev1}
gpart create -s gpt ${dev2}
gpart add -b 34 -s 64k -t freebsd-boot ${dev1}
gpart add -s ${swapsize} -t freebsd-swap -l swap0 ${dev1}
gpart add -s ${zfssize} -t freebsd-zfs -l disk0 ${dev1}
gpart add -b 34 -s 64k -t freebsd-boot ${dev2}
gpart add -s ${swapsize} -t freebsd-swap -l swap1 ${dev2}
gpart add -s ${zfssize} -t freebsd-zfs -l disk1 ${dev2}
gpart bootcode -b /boot/pmbr -p /boot/gptzfsboot -i 1 ${dev1}
gpart bootcode -b /boot/pmbr -p /boot/gptzfsboot -i 1 ${dev2}
zpool create ${poolname} mirror /dev/gpt/disk0 /dev/gpt/disk1
```

That worked perfectly for half a year. Suddenly, it wouldn't come back up after a reboot.

What I want to do now is mount the filesystem and check for misconfiguration. So I once again booted into the linux-based rescue system, *dd*'d mfsbsd onto the first disk (/dev/sda), booted it up. This FreeBSD-based system is called "prealpha". That's where I am now:


```
prealpha# gpart show 
=>        0  976773168  ada0  BSD  (466G)
          0         16        - free -  (8.0K)
         16      65520     1  !0  (32M)
      65536  976707632        - free -  (466G)

=>       34  976773101  ada1  GPT  (466G)
         34        128     1  freebsd-boot  (64K)
        162    8388608     2  freebsd-swap  (4.0G)
    8388770  629145600     3  freebsd-zfs  (300G)
  637534370  339238765        - free -  (162G)
prealpha# ls /dev/gpt/
disk1	swap1
```

The devices changed name from ad4/ad6 to ada0/ada1 because mfsbsd loads the ahci module now. I want to mount the zpool from ada1, and view/edit some configuration files. After that, I want to restore the mirror setup with with ada0 and ada1 and try to boot again.

How do I do that? Any help would be appreciated, I probably forgot to mention vital details, I am in a bit of a panic right now. Please tell me if you need more details.


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