Ceph (I): Basic Architecture

Recently I did a basic architecture document (and training) of ceph.

This document will give you the basics to understand the role of the Ceph architecture pieces like can be:

    • Monitor Nodes
    • Disk (aka OSD) nodes
    • Metadata Nodes
    • Gateway Nodes

And what the words “RADOS” and “CRUSH” means (again is a very basic definition)

Enjoy with the document/presentation!


I’ve been thinking about performing a level+99 sorcery and trying to bring back to life my blog.
Well, the moment has arrived.
I’m on a new stage on my professional life (also my private life) and there are new acquired knowledge to share.
So… keep reading!

Problems after upgrade mariadb

As you should know, there’s an important bug on TLS libs on every linux OS.
So upgrade is mandatory.
There’s also another little update in mariadb if you’re using it instead of mysql.
The problem is there, but not the indicator.

The problem in my case comes from the smtp server, I got the error:

535 5.7.8 Error: authentication failed: authentication failure

While tring to send an email (only sending, receiving works fine).
Looking in mail.log:

Mar  6 10:49:06 ciberterminal postfix/smtpd[29949]: warning: SASL authentication failure: Password verification failed
Mar  6 10:49:06 ciberterminal postfix/smtpd[29949]: warning: localhost.localdomain[]: SASL authentication failed: authentication failure

Auth failed from SASL? WTF!
So i began debuging it:

/usr/sbin/saslauthd -a pam -c -m /var/spool/postfix/saslauthd -r -n 1 -d -VVVVVVVVVV

But it only shows:

do_auth: auth failure: [user=dodger@ciberterminal.net] [service=smtp] [realm=ciberterminal.net] [mech=pam] [reason=PAM auth error]

Anything else.
Searching internet, I saw that post, I forgot to look for errors on auth.log!
Here it is:

Mar  7 10:48:41 ciberterminal saslauthd[4552]: PAM unable to dlopen(pam_mysql.so): /lib/security/pam_mysql.so: symbol make_scrambled_password, version libmysqlclient_18 not defined in file libmysqlclient.so.18 with link time reference
Mar  7 10:48:41 ciberterminal saslauthd[4552]: PAM adding faulty module: pam_mysql.so
Mar  7 10:48:41 ciberterminal saslauthd[4552]: DEBUG: auth_pam: pam_authenticate failed: Module is unknown
Mar  7 10:48:41 ciberterminal saslauthd[4552]: do_auth         : auth failure: [user=trian@ciberterminal.net] [service=smtp] [realm=ciberterminal.net] [mech=pam] [reason=PAM auth error]

Continue reading “Problems after upgrade mariadb”

Script to check Oracle remotely (nagios or whatever)

For all of you that are not the lucky owner of an Enterprise Manager license or you simply want to use nagios or another monitoring engine to get status and graphs of oracle, probably you’ll be using the “check_remote_oracle” plugin.

If you’re a scripter/developer maybe you’ll understand me when you open an script and see an COMPLETELY UNREADABLE code, with no functions, no indentation… etc
And then you’ll have to change anything stupid inside the script and then f**k it does not work!

This is the story of that script, I installed it, then I have to do some changes… and then I decided to rewrite it completely…
I’m not the best scripter of the world, but I know how to use functions, indentation and that useless shit :-P

You can read the whole documentation on its wiki page.


PS: updated the instructions, I forgot the information about the unprivileged user for connecting to Oracle instance.
PS2: Updated again, new control!

Openvpn in the TP-LINK WR841N[D]

Hi folks,
Here comes a post to improve that great router from TP-LINK.
Of course, I suppose you’re running openwrt on it to use the whole power of it.
The 1st I saw was that you have available a plenty set of packages… but you don’t have enough ROM to install them :-P
Inspecting a bit, I saw that under /tmp you have a “lot” of free space! (about 14MB), that will be enough to allow run openvpn without problems.
The main problem? Its a ramdisk, so each boot, everything there disappears.
What I’ve done? Install the basics with opkg and wget on boot the rest ;-)


Continue reading “Openvpn in the TP-LINK WR841N[D]”

Tablespace Usage on Oracle

I know that there are TONS of query’s like that, all of them different, of course.
What I’ve found is that some of them consider the max space of the tablespace as the current space… but what happens if the tablespace has “AUTOEXTEND ON”??
And the same with the “other” case… If you query for MAXBYTES and you have tablespaces with “AUTOEXTEND OFF” then the space reported will be 0 …
What I do with this query is use a “CASE” to report the correct MAXIMUM space, either if the tablespace has autoextend or not.

Continue reading “Tablespace Usage on Oracle”