[geeks] Raw disk access under Solaris

[JP Hindin]

On Tue, 6 Sep 2016, Patrick Giagnocavo wrote:

> I think if /dev/rdsk/c0t0dwhatever exists, you can use dd on that.  /dev/rdsk is "give me the raw disk access" while /dev/dsk has some kernel mediation/interference going on.

Unfortunately the kernel also enumerates /dev/rdsk/ in the same manner as 
/dev/dsk/, and so I believe it is also trying to use a non-existant 
partition map to figure itself out.

Either way, using /dev/rdsk/c3t0d0s2 gives the same 'I/O Error' message 
with no bytes transferred.

I appreciate all the suggestions so far;

  - JP

> ----- Original Message -----
> From: "JP Hindin" <jplist2008 at kiwigeek.com>
> To: "The Geeks List" <geeks at sunhelp.org>
> Sent: Tuesday, September 6, 2016 8:59:38 AM GMT -07:00 US/Canada Mountain
> Subject: Re: [geeks] Raw disk access under Solaris
>
> On Tue, 6 Sep 2016, Jonathan Katz wrote:
>> On Tue, Sep 6, 2016 at 3:22 PM, JP Hindin <jplist2008 at kiwigeek.com> wrote:
>>> Mornin' all, hopefully you (US'ns at least) had relaxing long weekends;
>>
>> I only had a long weekend in Belgium because I'm sick :( Anyway, here
>> is what you may be running into.
>>
>> Your disk is NOT a Sun disk. Therefore it likely does NOT have a Sun
>> (BSD) disk label. That means the c#t0d0s2 doesn't "exist" and that it
>> won't cover the whole disk. When you run the "format" command and
>> point at at this disk, does it say "Corrupt Disk or NO Sun disk label"
>> (or a similar error?) That's your issue. That said I'm not sure what
>> the right way is to image the whole disk in this instance. Do you get
>> any love from "prtvtoc" on the drive?
>
> Hmz, apparently I didn't make this belief clear enough in my original
> eMail - I'm also very certain this is precisely what is happening. Solaris
> provides appropriate 'invalid disk label' errors on boot and a prtvtoc
> very much has no interest in working with the drive.
>
> The disk is from a Cray J90, it is very, very definitely not partitioned
> in any way that Solaris is going to understand - that being said, it's
> just a string of bytes from one end of the drive to the other, partition
> maps are irrelevant to the data that's on the disk. Under Linux I'd just
> do a 'dd if=/dev/sdc ...' and all would be well.
> I simply don't know the Solaris mechanism to accomplish this.
>
> Feel better Jonathan;
>
>  - JP
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