FreeBSD 4.8: can't load kernel after doing "cp -R /" to another disk

[admin at azuni.net]

Tijl Coosemans wrote:
> On Sunday 30 November 2008 06:57:29 admin at azuni.net wrote:
>>>> Hello, everyone. This is the problem: our SCSI disk with FreeBSD
>>>> 4.8 on it has been failing recently, so I copied its root partition
>>>> to a fresh IDE disk with cp -pR and
>>> You should use dump and restore to copy the root partition, see:
>> I'd done that before trying cp -pR, as outlined by rse@:
>>
>> dump -L -0 -f- /old | (cd /new && restore -r -v -f-)
>> http://people.freebsd.org/~rse/mirror/
>>
>> which isn't too different. I think I know what the problem is: I made
>> the new single slice and FreeBSD partition on it and ran newfs -U on
>> it using the latest FreeBSD 5.x livecd toolkit, and later 4.8 can't
>> even mount that partition (mount /dev/ad0s1a /mnt) failing with
>> "incorrect superblock", so I think its /boot/loader can't load the
>> kernel because of FS issues (but strangely enough pressing "?" at the
>> boot loader prompt lists directory entries of the root FS just fine).
>> It turns out UFS isn't upwards compatible from releases 4.8 -> 5.5.
>> I'll try running newfs -U from 4.8. Last time I checked many 4.8
>> binaries couldn't run due to disk errors, I hope newfs runs ok...
> 
> You need to create a UFS1 file system.

Thanks a lot, I had forgotten about different UFS versions being used, 
and loader's showing the list of files when pressing "?" only poured 
more oil on the fire. This was really it.