Gmirror'd SWAP: no dump?

Larry Rosenman ler at
Thu Jan 19 11:27:42 PST 2006

Craig Boston wrote:
> On Thu, Jan 19, 2006 at 02:53:42PM +0000, Thomas Hurst wrote:
>>> IIRC I had the problem that 'gmirror insert' without '-h' not always
>>> inserted the slice specified by the entire block device (e.g.
>>> /dev/ad4s1 vs. /dev/ad4). Apparently there is some auto detection
>>> code and/or gmirror cannot differ correctly, but that's just a
>>> guess. Specifing '-h' fixed it in my case.
>> As I understand it, gmirror writes its metadata on the last sector of
>> the provider; when tasting devices it will look at the last sector of
>> ad4, find the metadata and use that as the provider for your mirror;
>> you can either hardcode the provider name there to override it, or
>> make the slice 1 sector smaller so gmirror tastes ad4, finds
>> nothing, then goes on to taste ad4s1 correctly.
> This was fixed for most cases by adding the size of the provider to
> the metadata.  ad4 should be a different size than ad4s1 as the
> partition table has to go somewhere...
> Looks like it was fixed in HEAD in Feb 2005, and MFC'd to 5.x in
> March. Shouldn't have ever been a problem for 6.x release.
Hrm.  With using the method for slices as specified on the ~rse page, I got

With specifying the entire disk, it works as normal, but no dump device.

Suggestions on how to enable dump, **AND** reliable boot would be


Larry Rosenman           
Phone: +1 512-248-2683                 E-Mail: ler at
US Mail: 430 Valona Loop, Round Rock, TX 78681-3893

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