Redundant VPN Tunnels via Different ISPs

Network Diagram or Whatever

Intro My friends will tell you that I’m obsessed with redundancy, both in life and in I.T. At home I have two main internet connections, via Altice Optimum (“cable”) and Verizon FiOS. They’re both relatively high bandwidth, and are connected to my two core routers that operate in an active/passive configuration. Basically this: O——O +——–+ / \ | |————/ O +——————+——————–| Core | / / | Optimum Router | | Router |———-O / +——————+\ ______________| 01 | \ O \ / | |————O \ \ / +——–+ / \ X Keepalived | / Various O / \ Heartbeat | O Networks / / \ +——–+ \ O +——————+/ \_____________| |———–\ \ | FiOS Router | | Core | \ O … Continue reading

RAID HDD TCO Calculator (Total Cost of Ownership)

HDD RAID TCO Worksheet Sample

A while back I created a HDD TCO worksheet showing the relative costs of certain drives in no real context. This spreadsheet aims to calculate the total cost of ownership for a RAID array, which is a much more involved affair. https://docs.google.com/spreadsheets/d/1dM2vO08gmX3VwYyJtTE5D1Gu75TTU-nUW95j1_DVx8c/ That’s a read-only version, but you can easily make your own copy to play with: If you have a Google account and are logged in, you can just hit File -> Make a Copy.. to save it to your own Google Drive. If you hate Google sniffing into your private affairs, you can hit File -> Download As and grab a copy in the format of your choice. I hope I’ve provided enough of an explanation as to … Continue reading

Yes, the Dell Compellent SC220 Chassis AND Drives are Generic!

The Compellent SC220 is the disk set on top, followed by an HP D2700, an HP MSA 70, and a Dell MD1220.

I found a great deal on eBay. A Dell Compellent SC220 chassis filled with 24 x 600GB 10K SAS disks for $350 including shipping. Obviously if you’re reading this years later that will seem like a terrible price, but as of now 600GB SAS drives are selling for about $30 each (used). So it’s roughly $720 worth of drives alone. The SC220 is basically an MD1220 in sheep’s clothing (though sheep are generally naked so who knows), and those are selling for about $120. Like I said, a great deal! But there was one question that needed answering: Did the Dell-branded Compellent HDDs have some kind of special firmware that rendered them useless with a standard RAID or JBOD controller? … Continue reading

Apparently myisamchk Doesn’t Understand 2-Digit Numbers (MySQL)

MySql Logo

myisamchk If you’re reading this, it’s probably because you’re trying to run myisamchk on a large table and you want to set the –sort_buffer_size to some large value. That’s advisable, of course. However, it seems that some versions of MySQL don’t understand a 2-digit value for that parameter. I was trying to do the following: myisamchk -f -r –update-state –key_buffer_size=4G –sort_buffer_size=16G –read_buffer_size=32M –write_buffer_size=32M /var/sql/myisam-temp/mastersitedb/applicants_master_search – recovering (with sort) MyISAM-table ‘/var/sql/myisam-temp/mastersitedb/applicants_master_search’ Data records: 0 – Fixing index 1 myisamchk: error: myisam_sort_buffer_size is too small MyISAM-table ‘/var/sql/myisam-temp/mastersitedb/applicants_master_search’ is not fixed because of errors Try fixing it by using the –safe-recover (-o), the –force (-f) option or by not using the –quick (-q) flag If you’re getting an error like that, try using … Continue reading

Sealed Lead Acid Battery Longevity Log

PowerPatrol_SLA_Batteries_from_Amazon_2

Atypical Post This post isn’t only for you, but also for me. I have roughly sixteen 120V 1300-1500VA UPSes in my basement of various ages. They each take two SLA 12V ~8Ah batteries. As such, I need to replace those batteries periodically. Being a cheap bastard, I don’t buy the branded APC or CyberPower packs, but go for inexpensive generics from eBay or Amazon. In theory there’s no difference, but in practice some cheap batteries are, well, cheap. I’m attempting to figure out which off-brand brands work best. This Log Hence I’m going to start logging battery replacements to get an idea of which brand(s) represent the best value and longevity. This will always be a work in progress, because … Continue reading

Amazon Echo Look – Teardown

Amazon Look - Teardown - All Parts - Top - YouTube Cover - Attempt 01 - 1080p

The Echo Look I’m working on a full review-type-thing of the Look, but who really cares about that? I’m sure people will want to see the insides of it, though. The most interesting two things on it are an Intel RealSense SR300 module (minus its visible light camera), and what’s basically a full Intel PC motherboard. In fact, here are the main specs: Intel Atom x5-Z8350 (SR2KT) @ 1.44Ghz (1.91Ghz burst) 8GB Samsung eMMC Flash NAND Storage 8GB Elpida LPDDR3 RAM Broadcom 802.11ac + 802.11b/g/a/n + Bluetooth (Not sure of the version) The hardware is fantastically made and well put together, and overall is very clever considering they stuffed all of it into a diminutive cylinder! The Reassembly I did … Continue reading

ZeroFiller: Nearly Fill Up a Disk with Zeroes for Snapshot Backups

ZeroFiller - Some Source Code - Screenshot

ZeroFiller (for Windows!) This might be a relatively niche utility, but I figured I’d share it because it might help someone in the same situation. File Version Description ZeroFiller-v0.8-20171023.zip v0.8a2017-10-23 The ZeroFiller executable only (requires .NET 4.5.2) ZeroFiller-src-0.8a-20171023.zip v0.8a2017-10-23 The ZeroFiller source code (requires >= Visual Studio 2017, probably) Backups I run a lot of VMs and I’m a bit obsessed with backups. I do high-level backups (meaning files, DB data, configs, etc.), as well as low-level backups of the actual VM disk images. The raw virtual disks get snapshotted on the host system, then the snapshot’s raw data is backed up using dd, gzip, and rsync. It’s not fancy, and it basically grabs the machine in a crashed state … Continue reading

Enterprise Network Switches for the Home: Ramble feat HP Procurve 5406ZL

The HP Procurve 5406ZL and…

…a whole lot of other crap, vis a vis my opinions on used enterprise-grade networking hardware for the home (or small-ish business).

I purchased an HP Procurve 5406ZL on eBay mainly because I “need” 10GbE on my home network, which is almost recursive because it’s for editing 4K video, which I need for editing this video.

The bottom line for me is that you can’t beat the feature/price ratio when it comes to equipment like this. That is, if you can afford the resultant power bill.

Razer DeathAdder Button Swap (Left- to Right-Handed Mouse)

Razer DeathAdder Button Swap

I’m a leftie, but all my life I’ve used right-handed mice in my left hand. I needed to replace my old Microsoft Optical Mouse, and found the DeathAdder Left-Handed Edition. It’s the perfect size and shape for me, but they did the weird thing of switching the left- and right-click buttons. It’s easy enough in most any operating system to swap the buttons in settings. However — at least with Windows — the buttons are only changed locally. So when connecting to other hosts via Remote Desktop the buttons revert to their hardware configuration. That’s a no-go for me, but I liked the mouse so much that I decided to mod the hardware instead. Fortunately, it’s very easy to reconfigure … Continue reading

Choosing a Disk Drive: HDDs, SSDs, and Then Some

This video covers almost everything you need to know about HDDs and SSDs to make an educated choice before pulling the trigger on a purchase.

Well, almost everything. This video is primarily directed at the home user trying to get some additional storage, whether that be an extra drive in their workstation, a NAS, or a full file server. If you’re trying to choose between SAS drives for a large-scale datacenter installation, then you probably know this stuff already.

As I promised in the video, here’s some links to my HDD TCO worksheet from 2013 (though I may have updated it in the interim with a couple of “new” drives). Please download the Excel version and use this for any drive that you want. If you make any interesting changes or large scale updates, I’d love to see it, so please let me know!

I also added a bunch of notes so you know what I meant with all the field names.

HDD Total Cost of Ownership Worksheet (Google Sheets – View only)

HDD Total Cost of Ownership Worksheet (Excel – View and edit)