# Install FreeBSD 9 on UFS1



## tangi (Apr 11, 2013)

I didn't find where to choose UFS1 instead of UFS2 while installing FreeBSD 9.
It was possible with 8.X versions.

All I have is: 

```
ada0         99.8 GB  GPT
    ada0p1   64 kB    freebsd-boot
    ada0p2   99.8 GB  freebsd-ufs
<Create> <Delete> <Modify> <Revert> <Auto> <Finish>
```
Thanks.


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## wblock@ (Apr 11, 2013)

You will probably have to run newfs(8) manually.  But why do you want to use UFS1?


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## tangi (Apr 11, 2013)

That's because linux supports only UFS1 mount write.


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## fonz (Apr 12, 2013)

tangi said:
			
		

> That's because l[red]L[/red]inux supports only UFS1 mount write.


Do you wish to have your entire FreeBSD filesystem hierarchy available for R/W mounting under Linux, or just part of it (e.g. /home or something)?

In the former case: UFS1 support appears to have been dropped from the installer so, as @wblock already pointed out, you'll have to manually create the filesystem(s). Let us know if you need help with that.

In the latter case: if the filesystem you wish to access from Linux is anything except the root filesystem, you might be better off creating a separate partition, initially making it UFS2, backing it up (if the installation procedure puts anything in there, that is), re-running newfs(8) to create a UFS1 filesystem instead and (if necessary) restoring the contents.


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## mlsemon (Apr 13, 2013)

> That's because linux supports only UFS1 mount write.



No, Linux supports UFS2 read/write just fine, it's just marked as EXPERIMENTAL in the kernel configuration. The configuration variables for Linux can be shown like this:


```
mls:~$ zcat /proc/config.gz | grep UFS
CONFIG_UFS_FS=y
CONFIG_UFS_FS_WRITE=y
# CONFIG_UFS_DEBUG is not set
```

Note that it is EXPERIMENTAL for a reason, and judging from outside the box, Linux UFS2 write support doesn't update all the FS structures. So if you write to UFS2 from Linux, be sure to have FreeBSD `fsck` the partitions before using them, preferably with the -y flag. In all cases I've seen, `fsck` updates the block counts that Linux didn't update, nothing more.

Still, having a shared junk partition would ultimately be a safer choice than having both systems write to the FreeBSD / over and over again. As much as "backups! backups! backups!" is a good motto, an accidental backup of a corrupted partition would probably be bad.


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## mlsemon (Apr 13, 2013)

I forgot, the UFS2 read/write mount option goes something like this from Linux, if you have the UFS write support in your kernel:

[cmd=]mount -t ufs -o rw,ufstype=ufs2 /dev/sdb1 /mnt/mount_point [/cmd]


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## tangi (Apr 14, 2013)

mlsemon said:
			
		

> I forgot, the UFS2 read/write mount option goes something like this from Linux, if you have the UFS write support in your kernel:
> 
> [cmd=]mount -t ufs -o rw,ufstype=ufs2 /dev/sdb1 /mnt/mount_point [/cmd]



Thanks for the tips. I will try if that works.


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