ata controller problem

Jeremy Chadwick jdc at
Fri Oct 26 16:33:40 UTC 2012

Regarding this:

No no NO *NO*!

I wish people would stop recommending this utter garbage.  There is
absolutely no justification behind using the highly convoluted labelling
mechanisms at multiple layers within FreeBSD.  There are 3 (possibly 4)
different "label" mechanisms which do nothing but confuse the user, or
cause other oddities/complexities.  Good grief, there is so much hard
evidence on the mailing lists over the past 5 (maybe even 7?) years
talking about the utter mess that is filesystem/device/geom/blahblah
labels that to recommend this is borderline insane.

The proper way to solve this problem is to user /boot/loader.conf
tie-downs to assign each disk to each individual controllers' device
number (e.g. ada0 --> scbus0 --> ahcich0, or whatever you want).  Please
note I said ahcichX, not ahciX.  Different things.

I have helped others in the past do this; Randy Bush is one such person.

Taken directly from my /boot/loader.conf with a single SATA controller,
but obviously this can be adjusted to whatever you want.

# "Wire down" device names (ada[0-5]) to each individual port
# on the SATA/AHCI controller.  This ensures that if we reboot
# with a disk missing, the device names stay the same, and stay
# attached to the same SATA/AHCI controller.

See CAM(4) man page (read it, don't skim!) for full details.  Just
please for the love of god do not use labels to solve this.

| Jeremy Chadwick                                   jdc at |
| UNIX Systems Administrator       |
| Mountain View, CA, US                                            |
| Making life hard for others since 1977.             PGP 4BD6C0CB |

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