February 16, 2012

Securing SSH with Publicly Accessible Servers

Just about every IT environment has some sort of remotely managed environment which requires that they have SSH open to the Internet.  Perhaps this is a VPS, dedicated server, or colocation.  Regardless of your reason, the fact is that there is just some times where you need to have SSH open to the internet. However regardless of if it is necessary doesn’t mean that you […]
February 15, 2012

vCenter: VPXD Crash

Recently I was trying to resolve an issue on a small vCenter 5.0.0 deployment.  Basically the primary symptom of the issue was that the service the vmware-vxpd service was crashing and needing to be restarted frequently. The first thing I did was examine the log files, while the service was still in a failed state. I won’t bore you with an entire excerpt, however I […]
February 6, 2012

KVM Guests: Graceful Shutdown

So a fairly trivial (but critical) aspect of using KVM is of course performing graceful shutdowns of your domains, without having to reach inside of the guest to perform the shutdown.  Now when it comes to turning off your guests you have two ways of proceeding (with virsh)… Which is a HARD power off of your guest.  This is the same as pulling the power […]
February 3, 2012

The Changing Face of Enterprise Support

Now let me preface this post by saying… I am writing this article from my professional experiences, inside of a software company which provided enterprise support for its products, as well as from the perspective of the Enterprise Customer.  I am intentionally discarding all experiences with support as a home user, and even as a small business owner.  This is specific to Enterprise Support, consumer […]
January 18, 2012

Adventures in ZFS: Crucial M4 Firmware SMART Issue

Let me preface this article by stating that this issue is NOT a ZFS issue or a Solaris issue.  Previously I documented a issue in which the Crucial M4 SSD would “hesitate” causing ZFS to see it as faulted.  This was promptly fixed in v0002 of their firmware.  That issue is documented here.  This issue is a bit more aggravating and has not been fully […]
January 16, 2012

Installing OpenIndiana in a Xen DomU

So I am on the ground in Dallas and trying to get my head around some of the technologies that we use in my new environment.  One of those being the Xen kernel.  I have never actually used Xen before, though I have used xenserver a bit.  Anyways so my first foray into the Xen world is trying to get OpenIndiana (successor to OpenSolaris) running […]
January 12, 2012

Mass Extraction and Creation of Tarballs

I have been working on creating a bunch of debootstrap images lately, and I ended up doing a whole bunch of work creating tarballs and did it wrong.  So I took the time to sort out an easy way to fix them all with two commands. The Core of My Problem So what started this is I forgot to “stand” in the directory I was […]
November 8, 2011

SSH Hop Through Multiple Hosts

I frequently need to ssh through multiple hosts to get to a destination.  Frankly this is not really a problem, but there is a simpler way, and I like simpler.  This is a really straight forward article, not a lot of explanation is really necessary.  Sometimes I need to use this when I am connecting through hosts that are not fully routed, or perhaps to […]
November 7, 2011

Linux-KVM: Converting Raw Disk Images to LVM Logical Volumes Redux

This really is an update to my previous article “Linux-KVM: Converting Raw Disk Images to LVM Logical Volumes“, but the process is significantly different and thus requires more explaining than a simple inline update would do it justice.  Now the big flaw with my first article was that by using dd on the hypervisor level, we are opening ourselves up to unintentional data loss due […]
November 2, 2011

Using Curl to Interact with Resource Records in Rackspace Cloud DNS

In this article we will be using curl to interact with Rackspace’s Cloud DNS to manipulate resource records in zones which already exist.  For details on how to use curl against Rackspace’s Cloud DNS API please see part one in this series “Using Curl to Access Rackspace Cloud DNS” in part two I documented the creation of DNS zones “Using Curl to Interact with Zones […]
November 1, 2011

Using Curl to Interact with Zones in Rackspace Cloud DNS

In my previous post “Using Curl to Access Rackspace Cloud DNS” we documented the basics of authenticating with the Rackspace Cloud for use with the Beta DNS service they offer, as well as doing basic queries against this service.  Today we are going to focus on creating our first domain, which no doubt will offer challenges for us, since it will require the uploading of […]
October 31, 2011

Using Curl to Access Rackspace Cloud DNS

Lately I have been looking at some cloud options for my more critical services, in this I have investigated Zerigo, Route 53, and Rackspace Cloud DNS.  Currently I have been focused on Rackspace DNS, since it is still free at this point, and frankly I’d rather not spend money on anything until I understand exactly how it works.  I have no experience with using “api” […]
October 4, 2011

Solaris 11: User Renames Not Simple Anymore

As part of the Solaris 11 Express Installation, you are required to create a named user, which is then the account you can log in as, no root for you.  Anyways the problem here is that we had some machines which we subsequently wanted to change the name.  Normally this would be simply handled by simple edits to the /etc/passwd and /etc/shadow.  However when we […]
September 6, 2011

Adventures in ZFS: Time Slider is not Expiring Snapshots on Imported Zpools

A few days ago someone contacted me with an interesting issue with regards to the ZFS automatic snapshots, facilitatedby the time slider service. The Situation OpenSolaris machine with zpool exported.  Time slider was working prior to export. Solaris 11 Express fresh install with zpool imported. The Symptoms Basically the core of the issue was that the zpool was from an OpenSolaris machine, in lieu of […]
August 24, 2011

Adventures in ZFS: Configuring Fibre Channel Targets

In our environment ZFS has become a critical component of our Storage Infrastructure.  We have been able to provision Fibre Channel storage from our ZFS file systems which give us the benefit of data integrity, deduplication, performance through use of the ARC, L2ARC, and ZIL as needed.  Additionally the real benefit to ZFS is our storage can run on commodity hardware which reduces the TCO […]
August 22, 2011

Adventures in ZFS: Timestamps Ruined My Rsync

So let me start out by saying…  This isn’t so much of a problem with ZFS, as it is just a problem with the tools available in Solaris (not to mention whatever device actually screwed up the timestamp in the first place).  But so here is the story.  We have found that migrating our lower level file servers to Solaris on top of deduped or […]
August 17, 2011

Traffic Limiting with PfSense 2.0 RC3

PfSense is a FreeBSD-based firewall distribution, which is extremely flexible for both businesses and individuals.  Additionally this platform can be installed on small ALIX hardware with Flash Memory as the storage all the way up to a full server deployment.  To give you an idea of speed, the small ALIX box (I have a few) is easily able to push 20Mbps.  I have a slightly […]
August 16, 2011

Linux-KVM Management: Live Migration Without Shared Storage

Everyday I learn something new about Linux-KVM, this is why I love this platform.  Today we are going to talk about Live Migration.  The kicker?  Shared storage not required.  Now please keep in mind that just because shared storage is not required, doesn’t mean there is not a benefit to it.  Shared storage will accelerate this process, since the data will not have to move.  […]
August 15, 2011

Adventures in ZFS: Faulted Cache Devices

We recently had an issue with Crucial M4 Solid State Disks when using them with ZFS on Solaris 11 Express (snv_151a).  Basically the disks were showing a whole bunch of write errors and had been “FAULTED” by ZFS. Now to make this problem even worse when we tried to zfs clear them it locked up my SSH session, as well as subsequent sessions, it would […]
August 10, 2011

Bash: Using Temporary SSH Keys Within A Script

Every once and a while you will have the need to make multiple ssh calls to remote systems within a bash script.  Normally you would simply have the user enter their password multiple times, or have a requirement for SSH keys to be configured prior to running the keys.  This is widely accepted as the way to do it, however if that were the best […]
August 9, 2011

Bash: Using pv to Display Progress of dd

One of the biggest weaknesses of dd is that it has no way to display progress on its actions.  You can send a signal to the process which will pause, display statistics, and resume the process however this takes up alot of your terminal screen if you are doing any sort of long running copy.  Enter pv.  Pv allows us to monitor the progress of […]
August 8, 2011

Linux-KVM Management: Offline Migration

When you compare Linux-KVM to Hyper-V or VMWare your initial results will indicate that Linux-KVM is lacking when it comes to management tools, and basic functionality.  You would be correct, however you would also be incorrect.  You see with Linux-KVM we can leverage the underlying power of the Linux userland, and with this frankly all things are possible.  Here is one of the basic bits […]
July 21, 2011

Identify Package Origin of Binary on Apt Systems

There will come a time when you need to install a package on a machine in order to take advantage of a utility contained within.  In my case I know that I need kvm-img (which is also called qemu-img), and I assumed that it was either in the libvirt-bin package or the qemu-kvm package.  It turned out for me that it was in qemu-kvm which […]
May 31, 2011

Solaris 11: Mount SMB Share Locally

Currently I have been working on a method of migrating some of our data from Windows file servers to Solaris ZFS CIFS servers, of course trying to retain as much feature parity as possible.  Permissions are an issue, however I have worked through most of those issues (look for this article in the future), now it is time to migrate data from Windows onto ZFS.  […]

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