foreach $webserver ( `cat servers` ) {
    $result = `ssh server cvs update ... `;
    if( echo $result | grep Error ) {
        echo 'problem with server $webserver'
    }
}

##</code><code>##

#! perl

my @webservers = <>;

for my $job ( @webserver ) {
    my $result = `ssh $job cvs update ...`;
    print "Server $job had errors" if $result =~ m[Error];
}

##</code><code>##

#! perl
use threads;

my @webservers = <>;
my @threads;
for my $job ( @webserver ) {
    push @threads, async{
        my $result = `ssh $job cvs update ...`;
        print "Server $job had errors" if $result =~ m[Error];
    };
}

$_->join for @threads.