Inproper ada# assignment in 10-BETA2

Mehmet Erol Sanliturk m.e.sanliturk at
Sat Sep 27 22:15:14 UTC 2014

On Sat, Sep 27, 2014 at 1:53 PM, Jin Guojun <jguojun at> wrote:

> Installed 10-BETA2 on SATA port 4 (ad8) and then added another SATA port 3
> (ad6), the system has not correctly enumerate the ada # for the boot device.
> As original boot (without the second SATA drive), the ad8 is enumerated as
> ada0 -- the boot drive:
> Sep 24 22:51:30 R10-B2 kernel: ada0 at ahcich2 bus 0 scbus2 target 0 lun 0
> Sep 24 22:51:30 R10-B2 kernel: ada0: <Hitachi HDP725050GLA360 GM4OA50E>
> ATA-8 SATA 2.x device
> ...
> Sep 24 22:51:30 R10-B2 kernel: ada0: Previously was known as ad8
> However, after added another SATA drive (ad6), this new drive is assigned
> to ada0, but ad8 has changed to ada1. This is incorrect dynamic device
> assignment. FreeBSD has kept using fixed disk ID assignment due to the same
> problem introduced in around 4-R (or may be slightly later), and after a
> simple debate, a decision was made to use fixed drive ID to avoid such
> hassle.
> If now we want to use dynamic enumeration for drive ID# assignment, this
> has to be done correctly -- boot drive MUST assigned to 0 or whatever the #
> as installation assigned to; otherwise, adding a new drive will cause
> system not bootable, or make other existing drive not mountable due to
> enumeration # changes.
> Has this been reported as a known problem for 10-R, or shall I open a bug
> to track?
> -Jin

One point should be checked :

On mainboards SATA ports are numbered from 0  or 1 to  upward .
BIOS always uses first SATA drive for boot .  This is NOT related to the
operating system .
Therefore , it is necessary to check port numbers of existing drives and
the bootable SATA drive should be connected
to the smallest numbered SATA port among existent drives .

For example , assume bootable drive is connected to SATA port 2 .
New drive should be connected to a higher numbered SATA port .
If there are only two SATA ports , then bootable drive should be connected
to the first SATA port .

If mainboard BIOS allows definition of any SATA port for boot , and
bootable SATA port and drive is specified in there , again it may boot from
that drive . Up to now , I did not see any BIOS which supplies such an
ordering among SATA ports . Please check your BIOS for such a feature . If
it is present you may use it , otherwise it is necessary to reconnect SATA
cables .

Thank you very much .

Mehmet Erol Sanliturk

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