April 19, 2017

Got Certified!!!

Posted in Linux at 9:06 am by alessiodini


I passed the exam Redhat EX318!
Now I’m certified on RHEV as “RHCVA” – Redhat Certified Virtualization Administrator.
I have to thank a couple of friends: Giovanni Mancuso and Davide Giannlivigni, they helped me studying for the exam ( I did not take the course )

Thank you both!!!
😀

November 23, 2016

Redhat: How can I check virtualization prerequisites?

Posted in Linux at 11:45 am by alessiodini


Playing with virt commands, I found virt-host-validate .

It is very useful! If I run it from a virtual machine without nested virtualization enabled, I will have:

# virt-host-validate
QEMU: Checking for hardware virtualization : FAIL (Only emulated CPUs are available, performance will be significantly limited)
QEMU: Checking if device /dev/vhost-net exists : PASS
QEMU: Checking if device /dev/net/tun exists : PASS
QEMU: Checking for cgroup ‘memory’ controller support : PASS
QEMU: Checking for cgroup ‘memory’ controller mount-point : PASS
QEMU: Checking for cgroup ‘cpu’ controller support : PASS
QEMU: Checking for cgroup ‘cpu’ controller mount-point : PASS
QEMU: Checking for cgroup ‘cpuacct’ controller support : PASS
QEMU: Checking for cgroup ‘cpuacct’ controller mount-point : PASS
QEMU: Checking for cgroup ‘cpuset’ controller support : PASS
QEMU: Checking for cgroup ‘cpuset’ controller mount-point : PASS
QEMU: Checking for cgroup ‘devices’ controller support : PASS
QEMU: Checking for cgroup ‘devices’ controller mount-point : PASS
QEMU: Checking for cgroup ‘blkio’ controller support : PASS
QEMU: Checking for cgroup ‘blkio’ controller mount-point : PASS
QEMU: Checking for device assignment IOMMU support : WARN (Unknown if this platform has IOMMU support)
LXC: Checking for Linux >= 2.6.26 : PASS
LXC: Checking for namespace ipc : PASS
LXC: Checking for namespace mnt : PASS
LXC: Checking for namespace pid : PASS
LXC: Checking for namespace uts : PASS
LXC: Checking for namespace net : PASS
LXC: Checking for namespace user : PASS
LXC: Checking for cgroup ‘memory’ controller support : PASS
LXC: Checking for cgroup ‘memory’ controller mount-point : PASS
LXC: Checking for cgroup ‘cpu’ controller support : PASS
LXC: Checking for cgroup ‘cpu’ controller mount-point : PASS
LXC: Checking for cgroup ‘cpuacct’ controller support : PASS
LXC: Checking for cgroup ‘cpuacct’ controller mount-point : PASS
LXC: Checking for cgroup ‘cpuset’ controller support : PASS
LXC: Checking for cgroup ‘cpuset’ controller mount-point : PASS
LXC: Checking for cgroup ‘devices’ controller support : PASS
LXC: Checking for cgroup ‘devices’ controller mount-point : PASS
LXC: Checking for cgroup ‘blkio’ controller support : PASS
LXC: Checking for cgroup ‘blkio’ controller mount-point : PASS

November 16, 2016

Opensource day 2016!!

Posted in Linux tagged , at 1:33 pm by alessiodini


Yesterday I have been with colleagues at OpenSource Day in Rome!
It was first time for me and I was so funny following Redhat Speech, Labs and much more.
I also saw old and ex colleagues.
I took some picture:

Rome, Palazzo dei congressi

Me

Colleagues

August 4, 2016

Openbaton 2 Installation

Posted in Linux at 12:10 pm by alessiodini


Today I installed with a collegue a basic openbaton environment on a Ubuntu 16 server. Customer needs an NFV ETSI Orchestration environment. I began the task installing and configuring the basic modules, it was very easy and funny!

This is the dashboard 🙂

April 11, 2016

LPIC remote labs

Posted in Linux tagged , , , , , , , at 2:22 pm by alessiodini


I’m working on funny idea: looking on the web I read that a lot of people need linux systems to study for LPIC-1 exam. I want to make Centos and Ubuntu remote avaiable systems with a very very low price for the rent! With this method , each one can play and test LPIC-1 topics without have a full computer.
You just need a putty client or web browser , so even a tablet is enough 😉

March 10, 2016

Linux ACL & standard permission question

Posted in Linux at 10:07 am by alessiodini


After long time , yesterday I played a bit with ACL on Redhat 6.7 nodes.
Doing some experiment I saw a strange thing:


[root@node1 ~]# useradd pippo
[root@node1 ~]# touch alessio
[root@node1 ~]# chmod 400 alessio
[root@node1 ~]# setfacl -m u:pippo:rwx alessio

[root@node1 ~]# getfacl alessio
# file: alessio
# owner: root
# group: root
user::r--
user:pippo:rwx
group::---
mask::rwx
other::---

[root@node1 ~]# chmod 600 alessio
[root@node1 ~]# getfacl alessio
# file: alessio
# owner: root
# group: root
user::rw-
user:pippo:rwx #effective:---
group::---
mask::---
other::---

This could be a noob question… but why acl changes from rwx to —?
I suppose there is a relationship between ACL configured and those initial standard permissions.
I need to know more about it! 🙂

September 19, 2015

Redhat Openstack 7 Undercloud Installation Bug

Posted in Linux at 6:46 pm by alessiodini


In these days I’m working with Redhat Openstack 6/7 versions.

When I install the undercloud component i got this error:

WARNING: keystoneclient.auth.identity.generic.base Discovering versions from the identity service failed when creating the password plugin. Attempting to determine version from URL.
WARNING: keystoneclient.auth.identity.generic.base Discovering versions from the identity service failed when creating the password plugin. Attempting to determine version from URL.
WARNING: keystoneclient.auth.identity.generic.base Discovering versions from the identity service failed when creating the password plugin. Attempting to determine version from URL.
ERROR: openstack Could not determine a suitable URL for the plugin
+ openstack role create ResellerAdmin
WARNING: keystoneclient.auth.identity.generic.base Discovering versions from the identity service failed when creating the password plugin. Attempting to determine version from URL.
WARNING: keystoneclient.auth.identity.generic.base Discovering versions from the identity service failed when creating the password plugin. Attempting to determine version from URL.
ERROR: openstack Could not determine a suitable URL for the plugin
[2015-09-19 19:58:29,620] (os-refresh-config) [ERROR] during post-configure phase. [Command ‘[‘dib-run-parts’, ‘/usr/libexec/os-refresh-config/post-configure.d’]’ returned non-zero exit status 1]

[2015-09-19 19:58:29,621] (os-refresh-config) [ERROR] Aborting…
Traceback (most recent call last):
File “”, line 1, in
File “/usr/lib/python2.7/site-packages/instack_undercloud/undercloud.py”, line 526, in install
_run_orc(instack_env)
File “/usr/lib/python2.7/site-packages/instack_undercloud/undercloud.py”, line 461, in _run_orc
_run_live_command(args, instack_env, ‘os-refresh-config’)
File “/usr/lib/python2.7/site-packages/instack_undercloud/undercloud.py”, line 297, in _run_live_command
raise RuntimeError(‘%s failed. See log for details.’, name)
RuntimeError: (‘%s failed. See log for details.’, ‘os-refresh-config’)
ERROR: openstack Command ‘instack-install-undercloud’ returned non-zero exit status 1

I read a lot of times the official documentation and I looked on Redhat Solutions but I got stuck here.
With some analisys I found that if I add the netmask on undercloud_public_vip and undercloud_admin_vip directives the script uses the ip with the whole netmask:
( undercloud.conf)

undercloud_public_vip = 172.16.111.2/24
undercloud_admin_vip = 172.16.111.3/24

(…)
++ export OS_AUTH_URL=https://172.16.111.2/24:13000/v2.0
++ OS_AUTH_URL=https://172.16.111.2/24:13000/v2.0
++ hiera controller_public_vip
+ REGISTER_SERVICE_OPTS=’-p 172.16.111.2/24′
++ hiera controller_public_vip
+ INIT_KEYSTONE_OPTS=’-s 172.16.111.2/24′

Thats’ why the command gets an error!!!

If I don’t write the netmasks the command will configure both ip with /32 netmask!!!!

I updated the Redhat bug 1251271, I’m curious to see what Redhat will reply :))

September 4, 2015

Redhat Ceph Storage

Posted in Linux at 2:26 pm by alessiodini


From a couple of weeks I’m playing with Redhat Ceph Storage, experimenting the cluster and some feature but at the moment I need to reinstall all the systems because I destroyed them!! 🙂

I’m also interested in adding Ceph to Openstack and play with both together.
Starting from next week I will have 6 physical systems available for this purpose… let’s see what will happen! 🙂

November 28, 2014

How to play with VI editor and regex with a simple browser!

Posted in Linux tagged , , at 4:18 pm by alessiodini


I accidentally found this web emulator.
It’s well done and you can play with basic Linux commands, vi and regex.

It’s interesting, have fun!! 😀

November 26, 2014

Redhat on DL380P G8: Illegal OpCode error

Posted in Linux tagged , , , , , , at 2:11 pm by alessiodini


Recently I installed a RHEL 5.5 on HP DL380P G8.
I made a standard installation ( network , lvm , filesystems, packages ) and rebooting the system I got a red screen with error “illegal_opcode
I never faced this issue and I was thinking “Why??”
I was in front of the rack without my notebook and internet , so I called some colleague and they helped me looking on the web. After 1 hour I made some test without success and with a colleague we find a solution. Before the installation we made 2x volumes via raid hardware. The issue was with these 2 volumes because during the installation for some reason, Linux saved data on one disk and the GRUB on the other.
So, if u face this issue don’t panic!!
Just:

1) Boot in rescue mode and let it mount the filesystems
2) # df -h | grep boot ( remember the device and the mounted fs name )
2a) # umount -l ( in my case /mnt/sysimage/boot )
3) # chroot /mnt/sysimage
4) # mount /boot
5) # /sbin/grub-install ( in my case grub-install /dev/cciss/c0d1 )

Leave the chroot and reboot.
Good luck 🙂

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