Try writing your program without Thread::Pool, this works fine here, showing that Net::SSH2 is threadsafe.

I'm running this on perl 5.12.4 on Ubuntu 11.10. Please help me save the little hair

Make sure your Ubuntu version of Perl is compiled to use threads.... I seem to recall Ubuntu may install a non-threaded Perl as default.

#!/usr/bin/perl
use warnings;
use strict;
use threads;

my $thr;
for(1..10){
   $thr = threads->new( \&sub1 )->detach; # Spawn the thread
}

while(1){ 

  my $thread_count = threads->list();
  print "\n\n\n\t\t",'num threads ', $thread_count, "\n\n\n";
  print "Hit control c to exit \n\n\n\n";
  sleep 1;
 }

exit;

sub sub1 {
use Net::SSH2;

# assuming a user named 'z' for demonstration 
# connecting to localhost, so you need your sshd running

# see maillist archives at
# http://lists.sourceforge.net/lists/listinfo/ssh-sftp-perl-users
# for deeper discussions

my $self = threads->tid();

my $ssh2 = Net::SSH2->new();
$ssh2->connect('localhost') or die "Unable to connect Host $@ \n";
$ssh2->auth_password('z','ztester') or die "Unable to login $@ \n";

#shell use
my $chan = $ssh2->channel();
$chan->blocking(0);
$chan->shell();
print $chan "ls -la\n";
print "thread $self : $_" while <$chan>;

print $chan "who\n";
print "thread $self  : $_" while <$chan>;

print $chan "date\n";
print "thread $self  : $_" while <$chan>;
$chan->close;
}
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