I am trying to find the maximum number of device names supported  by
Solaris 9 and/or 10.
I cannot find any documented information on this topic and have
received conflicting information from their is no limit to the number
of device names supported by Solaris to various limits.  Can any one
clarify?

Regards,
whitson

YAA <youranass@comcast.net> writes:

>I am trying to find the maximum number of device names supported  by
>Solaris 9 and/or 10.
>I cannot find any documented information on this topic and have
>received conflicting information from their is no limit to the number
>of device names supported by Solaris to various limits.  Can any one
>clarify?

Where did you look and what limits did you find?

In 32 bit Solaris, the device numbers are 32 bit, divided into
a 14 bit "major" component (in other words, the number of allowable device
drivers) and a 18 bit "minor" component (in other words, the maximum
number of allowable devices of a particular type; 262144 minor
numbers, 16384 major numbers)

This division is arbitrary and perhaps not well thought out as
only now do we need 9 bits for major numbers and 18 bits for minor numbers
may run out on some outlandish systems.

For 64 bit Solaris, the division is 32/32.

Casper
-- 
Expressed in this posting are my opinions.  They are in no way related
to opinions held by my employer, Sun Microsystems.
Statements on Sun products included here are not gospel and may
be fiction rather than truth.

On May 16, 3:44 pm, YAA <youran...@comcast.net> wrote:
> I am trying to find the maximum number of device names supported  by
> Solaris 9 and/or 10.
> I cannot find any documented information on this topic and have
> received conflicting information from their is no limit to the number
> of device names supported by Solaris to various limits.  Can any one
> clarify?

I suspect the limit, if there is one, is quite a lot larger than the
number of devices you're likely to be able to physically glue onto a
box.  I imagine it's large enough to allow for something like an M9000
all in one domain with however-many-it-is (200?) PCI cards in it and
several devices on each one.

I think you need to give more detail.

On 17 May 2007 02:02:00 -0700 Tim Bradshaw <tfb+google@tfeb.org> wrote:
> On May 16, 3:44 pm, YAA <youran...@comcast.net> wrote:
>> I am trying to find the maximum number of device names supported  by
>> Solaris 9 and/or 10.
>> I cannot find any documented information on this topic and have
>> received conflicting information from their is no limit to the number
>> of device names supported by Solaris to various limits.  Can any one
>> clarify?
>
> I suspect the limit, if there is one, is quite a lot larger than the
> number of devices you're likely to be able to physically glue onto a
> box.  I imagine it's large enough to allow for something like an M9000
> all in one domain with however-many-it-is (200?) PCI cards in it and
> several devices on each one.
>
> I think you need to give more detail.

The max number of device names is a different problem than the max
number of *physical* devices that can be attached.

Do devices (and so device names) all need to have a unique major and
minor number?  Even pty's, it seems, get multiplexed by major and
minor number and not their actual name.

If so, the limit would be based on the size of the major/minor space.
16 bits?

I just noticed /dev/zfs has major number 256. heh.

-frank

Frank Cusack <fcusack@fcusack.com> writes:

>Do devices (and so device names) all need to have a unique major and
>minor number?  Even pty's, it seems, get multiplexed by major and
>minor number and not their actual name.

All devices have a unique <major, minor> combination.

Not all of those exist in the name space, though.

>If so, the limit would be based on the size of the major/minor space.
>16 bits?

14 for major, 18 for minor.

>I just noticed /dev/zfs has major number 256. heh.

My SunBlade 2000 has a major number of 319 for ds_pri (major numbers
are system specific and depend on the sequence of installs/upgrades
done)

Casper
-- 
Expressed in this posting are my opinions.  They are in no way related
to opinions held by my employer, Sun Microsystems.
Statements on Sun products included here are not gospel and may
be fiction rather than truth.

On 2007-05-17 10:37:49 +0100, Frank Cusack <fcusack@fcusack.com> said:

> The max number of device names is a different problem than the max
> number of *physical* devices that can be attached.

Yes, of course.  I'm just suggesting that it's probably comfortably 
larger as well, even for big machines, as I assume the Solaris 
engineers knw what they're doing.  So unless someone is inventing lots 
of pseudo devices of some kind it is not likely to be an issue.  hence 
the request for more detail :-)