# RAID for a PowerPC G5



## tuaris (Jul 27, 2012)

I have a Apple Mac Pro G5 with two SATA drives of identical sizes with FreeBSD 9.1 beta installed on the first drive (ada0).  I'm new to FreeBSD on powerpc64, so I'm not exactly sure about how storage is done.  Is it using GPT or is it using the Apple Partition Map, or is it using a mixture of both (like it's done with MBR on the PC)?  I accepted all the default options when installing.  Here is the output from:

[CMD=""]gpart show[/CMD]:



```
=>       18  390721950  ada0  APM  (186G)
         18       1600     1  apple-boot  (800k)
       1618  125829120     2  freebsd-ufs  (60G)
  125830738   12582912     3  freebsd-swap  (6.0G)
  138413650  252308318        - free -  (120G)

=>       64  390721904  ada1  APM  (186G)
         64  390721904        - free -  (186G)
```

If it's using GPT does that mean I can't mirror the entire disk, but instead mirror the individual partitions?  Or, is it safe to use the instructions from the handbook?

Also, I was thinking if I had to mirror by partitions, what would be the best way to mirror a ZFS partition that I plan on placing in the 120GB of free space.


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## wblock@ (Jul 27, 2012)

tuaris said:
			
		

> ```
> =>       18  390721950  ada0  [color="Red"]APM[/color]  (186G)
> 18       1600     1  apple-boot  (800k)
> 1618  125829120     2  freebsd-ufs  (60G)
> ...



That's Apple Partition Map on both drives.  No idea whether other partitioning schemes are bootable on the PPC Macs.


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## tuaris (Jul 28, 2012)

I attempted to enabled the geom_mirror as detailed here: http://www.freebsd.org/doc/handbook/geom-mirror.html.  After rebooting I am receiving this error:


```
Invalid memory access at &SRR0: 00000000.0743f4c &SRR1: 90000000.00003030
```

Same issue on the other identical system, the error is slightly different:


```
Decrementer exception at &SRR0: 00000000.0743f4c &SRR1: 90000000.00003030
```

I can't boot either of them at this point, but they are not important.  The two systems were built specifically for testing this.

Screen shots here.
http://www.daniel.morante.net/screenshot/IMAG0018.jpg
http://www.daniel.morante.net/screenshot/IMAG0022.jpg


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## tuaris (Aug 29, 2012)

The same issue continues to occur on FreeBSD 9.1-RC1.  I'll leave the two systems as is, just in case anyone wants me to try some stuff.


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## kpa (Aug 29, 2012)

As far as I know the handbook example is valid only for i386/amd64 and MBR partitioning. You should be able to mirror the root partition only however. 

- Boot from a live cd and make a backup of the root partition with dump(8) to an external disk.

- Partition the 2nd disk ada1 indentically with ada0.

- Create the mirror out of ada0s3 and ada1s3.

- Create a new filesystem on the mirrored partition with newfs(8).

- restore(8) the backup on the new mirrored filesystem.

- Adjust /etc/fstab on the restored system so that the root filesystem points to the mirrored one.


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