viernes, 9 de julio de 2010

Firewalling - Ver que firewall corta el paso con hping

Imaginamos un entorno de red complejo donde hay nose, 4 saltos entre nuestra máquina y un servidor. Dentro de estos saltos hay switchs, routers, firewalls, etc... Y queremos ver donde se esta cortando la comunicación por ejemplo el puerto 8080.

Hacemos un traceroute -In 192.168.1.4 para ver los saltos.
traceroute to 192.168.1.4 (192.168.1.4), 30 hops max, 52 byte packets
1 192.168.12.1 1.008 ms 0.540 ms 0.535 ms
2 192.168.23.33 1.670 ms 1.115 ms 1.111 ms
3 192.168.25.3 0.631 ms 1.156 ms 0.598 ms
4 192.168.1.4 1.444 ms 1.343 ms 1.281 ms

Con el comando hping podemos comprobar en que hop no pasamos

hping 192.168.1.4 -p 8080 -St 1
TTL 0 during transit from ip=192.168.12.1 name=router1
TTL 0 during transit from ip=192.168.12.1 name=router1
TTL 0 during transit from ip=192.168.12.1 name=router1

Ok por el hop 1 pasamos, probamos por el segundo
hping 192.168.1.4 -p 8080 -St 2
TTL 0 during transit from ip=192.168.23.33 name=UNKNOWN
TTL 0 during transit from ip=192.168.23.33 name=UNKNOWN

Ok por el hop 2 pasamos, probamos por el tercero
hping 192.168.1.4 -p 8080 -St 3
HPING 192.168.1.4 (eth0 192.168.1.4): S set, 40 headers + 0 data bytes
^C
No contesta. Ya sabemos que el firewall 192.168.25.3 nos corta el paso

martes, 6 de julio de 2010

Añadir nuevo disco iscsi multipath ocfs2

En cada nodo del cluster

Reescanemos en busca de la nueva lun
iscsiadm -m session --rescan

Recargamos multipath
/etc/init.d/multipathd reload

multipath -v3

Verificamos que vemos los caminos hacia la nueva LUN
multipath -ll

Creemos los enlaces uuid
(como no se como se hace automaticamente en Suse, lo hago a mano)
blkid | grep /dev/dm-

En este caso asumo que es /dev/dm-1 con el UUID 325dab18-903a-4aae-8230-a9662294846e
cd /dev/disk/by-uuid
ln -s ../../dm-1 325dab18-903a-4aae-8230-a9662294846e

verificamos que es correcto y ya lo tenemos listo para añadir como dispositivo en el recurso fs del cluster


En un nodo del cluster

Formateamos el nuevo disco

mkfs.ocfs2 -N 16 /dev/dm-2


En el CRM

Añadimos el recurso clone fs:ocf:heartbeat con sus respectivas constraints de localización, colocación y orden y listos. Nuevo pool de espacio libre.

viernes, 2 de julio de 2010

El comando seq - un buen amigo

Imaginemos que tenemos un directorio con 100 ficheros que se llaman server_log1.log, server_log2.log... hasta server_log100.log y nos interesa comprimir del 1 al 90. Con seq es así de fácil:

miramos que hace seq.
[ferran@myhost ferran]$ seq 1 90

1
2

3
..
90

Entonces si hacemos:
for i in `seq 1 90 ` ; do gzip server_log$i.log ; done

Seria como si a manita hiciéramos 90 veces...
gzip server_log1.log
gzip server_log2.log
gzip server_log3.log
..
gzip server_log90.log


viernes, 25 de junio de 2010

Arch linux en Active Directory

Con estos dos howtos está hecho :D

Arch server to Windows domain
http://wiki.archlinux.org/index.php/Arch_server_to_Windows_domain

Unir Linux a un Dominio Active directory
http://gnulinuxcodigo.blogspot.com/2009/12/unir-linux-un-dominio-active-directory.html

Stonith ibmrsa-telnet Suse SLES11

Según el departamento de ingeniería de Novell, el patch que adjunté anteriormente ya se incluye en el Service Pack 1 de SLES11.

Entonces el script queda así:



#!/usr/bin/python

# vim: set filetype=python

#######################################################################

#

# ibmrsa-telnet - External stonith plugin for HAv2 (http://linux-ha.org/wiki)

# Connects to IBM RSA Board via telnet and switches power

# of server appropriately.

#

# Author: Andreas Mock (andreas.mock@web.de)

#

# History:

# 2007-10-19 Fixed bad commandline handling in case of stonithing

# 2007-10-11 First release.

#

# Comment: Please send bug fixes and enhancements.

# I hope the functionality of communicating via telnet is encapsulated

# enough so that someone can use it for similar purposes.

#

# Description: IBM offers Remote Supervisor Adapters II for several

# servers. These RSA boards can be accessed in different ways.

# One of that is via telnet. Once logged in you can use 'help' to

# show all available commands. With 'power' you can reset, power on and

# off the controlled server. This command is used in combination

# with python's standard library 'telnetlib' to do it automatically.

#

# cib-snippet: Please see README.ibmrsa-telnet for examples.

#

# Copyright (c) 2007 Andreas Mock (andreas.mock@web.de)

# All Rights Reserved.

#

# This program is free software; you can redistribute it and/or modify

# it under the terms of version 2 or later of the GNU General Public

# License as published by the Free Software Foundation.

#

# This program is distributed in the hope that it would be useful, but

# WITHOUT ANY WARRANTY; without even the implied warranty of

# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

#

# Further, this software is distributed without any warranty that it is

# free of the rightful claim of any third person regarding infringement

# or the like. Any license provided herein, whether implied or

# otherwise, applies only to this software file. Patent licenses, if

# any, provided herein do not apply to combinations of this program with

# other software, or any other product whatsoever.

#

# You should have received a copy of the GNU General Public License

# along with this program; if not, write the Free Software Foundation,

# Inc., 59 Temple Place - Suite 330, Boston MA 02111-1307, USA.

#

#######################################################################

import sys

import os

import time

import telnetlib

import subprocess


class TimeoutException(Exception):

def __init__(self, value=None):

Exception.__init__(self)

self.value = value



def __str__(self):

return repr(self.value)


class RSABoard(telnetlib.Telnet):

def __init__(self, *args, **kwargs):

telnetlib.Telnet.__init__(self, *args, **kwargs)

self._timeout = 10

self._loggedin = 0

self._history = []

self._appl = os.path.basename(sys.argv[0])


def _get_timestamp(self):

ct = time.time()

msecs = (ct - long(ct)) * 1000

return "%s,%03d" % (time.strftime("%Y-%m-%d %H:%M:%S",

time.localtime(ct)), msecs)



def write(self, buffer):

self._history.append(self._get_timestamp() + ': WRITE: ' + repr(buffer))

telnetlib.Telnet.write(self, buffer)



def expect(self, what, timeout=20):

line = telnetlib.Telnet.expect(self, what, timeout)

self._history.append(self._get_timestamp() + ': READ : ' + repr(line))

if not line:

raise TimeoutException("Timeout while waiting for '%s'." % (what, ))

return line



def login(self, user, passwd):

time.sleep(1)

line = self.expect(['\nlogin : ', '\nusername: '], self._timeout)

self.write(user)

self.write('\r')

line = self.expect(['\nPassword: ', '\npassword: '], self._timeout)

self.write(passwd)

self.write('\r')

line = self.expect(['\nsystem>', '> '], self._timeout)



def reset(self):

self.write('power cycle\r')

line = self.expect(['\nok'], self._timeout)

line = self.expect(['\nsystem>', '> '], self._timeout)



def on(self):

self.write('power on\r')

line = self.expect(['\nok'], self._timeout)

line = self.expect(['\nsystem>', '> '], self._timeout)



def off(self):

self.write('power off\r')

line = self.expect(['\nok'], self._timeout)

line = self.expect(['\nsystem>', '> '], self._timeout)



def exit(self):

self.write('exit\r')



def get_history(self):

return "\n".join(self._history)



class RSAStonithPlugin:

def __init__(self):

# define the external stonith plugin api

self._required_cmds = \

'reset gethosts status getconfignames getinfo-devid ' \

'getinfo-devname getinfo-devdescr getinfo-devurl ' \

'getinfo-xml'

self._optional_cmds = 'on off'

self._required_cmds_list = self._required_cmds.split()

self._optional_cmds_list = self._optional_cmds.split()



# who am i

self._appl = os.path.basename(sys.argv[0])



# telnet connection object

self._connection = None



# the list of configuration names

self._confignames = ['nodename', 'ip_address', 'username', 'password']



# catch the parameters provided by environment

self._parameters = {}

for name in self._confignames:

try:

self._parameters[name] = os.environ.get(name, '').split()[0]

except IndexError:

self._parameters[name] = ''



def _get_timestamp(self):

ct = time.time()

msecs = (ct - long(ct)) * 1000

return "%s,%03d" % (time.strftime("%Y-%m-%d %H:%M:%S",

time.localtime(ct)), msecs)



def _echo_debug(self, *args):

self.echo_log('debug', *args)



def echo(self, *args):

what = ''.join([str(x) for x in args])

sys.stdout.write(what)

sys.stdout.write('\n')

sys.stdout.flush()

self._echo_debug("STDOUT:", what)



def echo_log(self, level, *args):

subprocess.call(('ha_log.sh', level) + args)


def _get_connection(self):

if not self._connection:

c = RSABoard()

self._echo_debug("Connect to '%s'" %

(self._parameters['ip_address'],))

c.open(self._parameters['ip_address'])

self._echo_debug("Connection established")

c.login(self._parameters['username'],

self._parameters['password'])

self._connection = c


def _end_connection(self):

if self._connection:

self._connection.exit()

self._connection.close()


def reset(self):

self._get_connection()

self._connection.reset()

self._end_connection()

self._echo_debug(self._connection.get_history())

self.echo_log("info", "Reset of node '%s' done" %

(self._parameters['nodename'],))

return(0)



def on(self):

self._get_connection()

self._connection.on()

self._end_connection()

self._echo_debug(self._connection.get_history())

self.echo_log("info", "Switched node '%s' ON" %

(self._parameters['nodename'],))

return(0)



def off(self):

self._get_connection()

self._connection.off()

self._end_connection()

self._echo_debug(self._connection.get_history())

self.echo_log("info", "Switched node '%s' OFF" %

(self._parameters['nodename'],))

return(0)



def gethosts(self):

self.echo(self._parameters['nodename'])

return(0)



def status(self):

self._get_connection()

self._end_connection()

self._echo_debug(self._connection.get_history())

return(0)



def getconfignames(self):

for name in ['nodename', 'ip_address', 'username', 'password']:

self.echo(name)

return(0)


def getinfo_devid(self):

self.echo("External Stonith Plugin for IBM RSA Boards")

return(0)



def getinfo_devname(self):

self.echo("External Stonith Plugin for IBM RSA Boards connecting "

"via Telnet")

return(0)

def getinfo_devdescr(self):

self.echo("External stonith plugin for HAv2 which connects to "

"a RSA board on IBM servers via telnet. Commands to "

"turn on/off power and to reset server are sent "

"appropriately. "

"(c) 2007 by Andreas Mock (andreas.mock@web.de)")

return(0)

def getinfo_devurl(self):

self.echo("http://www.ibm.com/Search/?q=remote+supervisor+adapter")



def getinfo_xml(self):

info = """





nodename to shoot



Name of the node which has to be stonithed in case.









hostname or ip address of RSA



Hostname or ip address of RSA board used to reset node.









username to login on RSA board



Username to login on RSA board.









password to login on RSA board



Password to login on RSA board.







"""

self.echo(info)

return(0)

def not_implemented(self, cmd):

self.echo_log("err", "Command '%s' not implemented." % (cmd,))

return(1)


def usage(self):

usage = "Call me with one of the allowed commands: %s, %s" % (

', '.join(self._required_cmds_list),

', '.join(self._optional_cmds_list))

return usage


def process(self, argv):

self._echo_debug("========== Start =============")

if len(argv) < 1:

self.echo_log("err", 'At least one commandline argument required.')

return(1)

cmd = argv[0]

self._echo_debug("cmd:", cmd)

if cmd not in self._required_cmds_list and \

cmd not in self._optional_cmds_list:

self.echo_log("err", "Command '%s' not supported." % (cmd,))

return(1)

try:

cmd = cmd.lower().replace('-', '_')

func = getattr(self, cmd, self.not_implemented)

rc = func()

return(rc)

except Exception, args:

self.echo_log("err", 'Exception raised:', str(args))

if self._connection:

self.echo_log("err", self._connection.get_history())

self._connection.close()

return(1)


if __name__ == '__main__':

stonith = RSAStonithPlugin()

rc = stonith.process(sys.argv[1:])

sys.exit(rc)


jueves, 17 de junio de 2010

Crear eth0 alias ifconfig

Por si necesitas crearte un alias temporal

ifconfig eth0:0 192.168.18.8 netmask 255.255.255.0 up

eth0:0 Link encap:Ethernet direcciónHW 00:21:9b:6c:d6:5a
Direc. inet:192.168.18.8 Difus.:192.168.18.255 Másc:255.255.255.0
ACTIVO DIFUSIÓN FUNCIONANDO MULTICAST MTU:1500 Métrica:1
Memoria:fe9e0000-fea00000

martes, 15 de junio de 2010

VMWARE ESX 4.0 VSphere Update Crash

Tras el último update, dos de los servidores vsphere han fallado al arrancar. El error aparece justo en el momento en que arranca udev. Al parecer esta actualización ha provocado que el UUID de la partición /var/log cambie.

SOLUCIÓN
Entrar con el passwd de root y remontar el filesystem / con rescritura
m
ount -o remount,rw /

Miramos que UUID tiene /var/log en el fichero /etc/fstab
UUID=315f724f-637f-4118-b755-2511f4ff04 /var/log ext3 defaults,errors=panic 1 2
Miramos el nuevo UUID
blkid

Veremos que uno de los UUIDs ha cambiado
/dev/sdv1: UUID="e2ac6711-87c4-45a8-8f2a-fe2e47f6fd3" SEC_TYPE="ext2" TYPE="ext3"
/dev/sdz1: TYPE="ntfs"
/dev/sdab1: TYPE="swap" UUID="a0e811ca-e8dd-4e28-b4b-cabdbe54936f"
/dev/sdab2: UUID="415f724f-637f-4118-b755-251f4ff0b14" SEC_TYPE="ext2" TYPE="ext3"
/dev/sdab5: LABEL="esx-root" UUID="7b52ed6d-c48-4c12-969f-68b66a0550c" SEC_TYPE="ext2" TYPE="ext3"

modificamos la línia del fichero /etc/fstab que hace referencia al montaje de /var/log con el nuevo UUID (si se esta editando con vi, se puede traer la salida del comando blkid haciendo en modo consola [ESC] :.!blkid )

UUID=415f724f-637f-4118-b755-251f4ff0b14 /var/log ext3 defaults,errors=panic 1 2

Guardamos :wq!

Reiniciamos el servidor y ya ha funcionado.



-Después de escribir este post hemos recibido un correo electrónico de vmware con las mismas instrucciones para solucionarlo de forma oficial :)