# atacontrol questions



## skye (May 27, 2015)

Hi, here's a question from the mists of time...

I'm in the process of recovering data from a very old server suffering from a failed 2-drive mirrored RAID array on FreeBSD 7.1.  I've identified and removed the bad drive, removed it from the server, and after a bit of fsck'ing and backup restoration I've got the remaining drive working OK.  The good drive was on ad6 (mirror) and I moved it to the first bay ad4 as recommended by the atacontrol(8) man page.  Here's my current boot log:


```
ad4: 238475MB <WDC WD2500JD-00HBC0 08.02D08> at ata2-master SATA150
ar0: WARNING - mirror protection lost. RAID1 array in DEGRADED mode
ar0: 238475MB <Intel MatrixRAID RAID1> status: DEGRADED
ar0: disk0 DOWN no device found for this subdisk
ar0: disk1 READY (mirror) using ad4 at ata2-master

# atacontrol list
ATA channel 0:
    Master: acd0 <TOSHIBA CD-ROM XM-6202B/1108> ATA/ATAPI revision 0
    Slave:       no device present
ATA channel 1:
    Master:      no device present
    Slave:       no device present
ATA channel 2:
    Master:  ad4 <WDC WD2500JD-00HBC0/08.02D08> Serial ATA v1.0
    Slave:       no device present
ATA channel 3:
    Master:      no device present
    Slave:       no device present
#
# atacontrol status ar0
ar0: ATA RAID1 status: DEGRADED
subdisks:
   0 ---- MISSING
   1 ad4  ONLINE
```
What I would like to do is to remove the bad master drive from the RAID1 completely, making the old mirror ad4 the new master.  The goal is to be able to insert the old drive back into the server WITHOUT it being recognized as part of the array, so I can do some stress testing on it to see if it's actually bad.  Is that possible?  Do I have to go out and buy an external enclosure just to test this old drive?  `atacontrol detach` seems to be for safely removing a drive from the physical system, not for actually reconfiguring the array.

Thanks in advance!


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## skye (May 28, 2015)

Here's a slightly different way to ask the same thing.  Same config and drives as previous post above.

If I `atacontrol delete ar0` can I boot from the remaining ad4 drive?  Is there any special format or header blocks on the drive from the RAID1 mirroring that would prevent using the drive outside of the array?

Also, do I have to configure the boot loader etc to boot from ad4 instead of ar0?

Thanks


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## gkontos (May 29, 2015)

This appears to be a BIOS pseudo RAID1. So, I think that this is the first place to start.


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## skye (Jun 2, 2015)

I don't see anything in BIOS setup or during boot, but I'll have another look.


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