linux

Get IPMI IP address from OS

Submitted by alvaro.soto on Thu, 11/21/2019 - 22:52

First check that you have ipmitool installed:

[root@lykan ~]# yum provides ipmitool Last metadata expiration check: 0:06:54 ago on Thu 21 Nov 2019 10:39:22 PM CST. ipmitool-1.8.18-10.fc29.x86_64 : Utility for IPMI control Repo : fedora Matched from: Provide : ipmitool = 1.8.18-10.fc29

Discover:

[root@lykan ~]# ipmitool lan print | grep "IP Address" IP Address Source : Static Address IP Address : 10.10.4.5

The complete information provided:

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Improve user experience using QEMU/KVM with Windows guest

Submitted by alvaro.soto on Tue, 10/01/2019 - 11:32

A lot of sysadmins, SRE o wherever you want to call us, using native Linux in our laptops have the need to use virtual machines running Windows (some support, pentesting tasks, etc), if you are passionate about running periodics updates by now you figure out the main problem of this, if not, you will; the main problem is that on every kernel upgrade you will lose the modules of vmware or virtualbox, the best solution for this is to use QEMU/KVM.

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How to Boot into Single User Mode in CentOS/RHEL 7

Submitted by alvaro.soto on Tue, 05/21/2019 - 12:39

DISCLAIMER: this is not my post is only a copy, in case the original get deleted or whatever, posting on my personal blog get easier for me to find it. You can find the original one in this link https://vpsie.com/knowledge-base/boot-single-user-mode-centos-rhel-vpsie/

The first thing to do is to open Terminal and log in to you CentOS 7 server.

After, restart your server wait for GRUB boot menu to show.

Next step is to select your Kernel version and press

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XFS online resize

Submitted by alvaro.soto on Wed, 04/17/2019 - 00:05

You're working on an XFS filesystem, in this case you need to use xfs_growfs instead of resize2fs. Two commands are needed to perform this task :

# growpart /dev/sda 1

growpart is used to expand the sda1 partition to the whole sda disk.

# xfs_growfs -d /dev/sda1

xfs_growfs is used to resize and apply the changes.

# df -h

Ceph recovery backfilling affecting production instances

Submitted by alvaro.soto on Wed, 06/14/2017 - 21:06

In any kind of distributed system you will have to choose between consistency, availability and partitioning, the CAP theorem states that in the presence of a network partition, one has to choose between consistency and availability, by default (default configurations) CEPH provides consistency and partitioning, just take in count that CEPH has many config options: ~860 in hammer, ~1100 in jewel, check this out, is jewel github co

Solve Ceph Clock Skew error

Submitted by alvaro.soto on Wed, 11/16/2016 - 01:21

Monitors can be severely affected by significant clock skews across the monitor nodes. This usually translates into weird behavior with no obvious cause. To avoid such issues, you should run a clock synchronization tool on your monitor nodes by default the monitors will allow clocks to drift up to 0.05 seconds.

This error can be seen using:

# ceph -s
# ceph health detail

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Cloning a Ceph client auth key

Submitted by alvaro.soto on Wed, 11/16/2016 - 00:54

I don't recall any reason to do this other than using the same user and auth key to authenticate in different Ceph clusters, like in a multi-backend solution, or just because things get messy when you are not using a default configuration.

Sometimes, things gets easy when we use the same user and auth key on both clusters for services to connect to, so lets see some background commands for managing users, keys and permissions:

Create new user and auth token (cinder client example):

Testing juju environment inside LXC container

I thing we pass the part of what juju is and how it works, so I'll post direct commands and configurations of how getting the environment working inside a LXC container, created just for juju, not the local configuration that creates and LXC container, in other words, out host server does not have any juju package.

Some links to read in case you need more info, or you can post a question.

alvaro.soto Sat, 03/12/2016 - 05:05