NAS – Experimental Engineering

Posted on April 1, 2017April 24, 2017 by The Engineer — Leave a comment

Website Hosting Updates!

Over the past few weeks, the host I’ve been with for over 3 years, OVH, announced a rather large price increase of 20% because of Brexit – the current universal excuse to squeeze the customer for more cash. This change has sent the price of my dedicated server solution with them to over £45 a month. Doing some napkin-calculation gave me £18 a month in extra power to run a small server locally. So I’ve decided to bring the hosting solution back to my local network & run from my domestic internet link, which at 200Mbit/s DL & 20Mbit/s UL should be plenty fast enough to handle the modest levels of traffic I usually get.

Obviously, some hardware was required for this, so I obtained this beauty cheap on eBay:

HP MicroServer Gen 8 — HP Proliant MicroServer Gen 8

This is a Gen 8 HP Proliant Microserver, very small & quiet, perfect for the job. This came with 4GB of RAM installed from the factory, and a Celeron G1610T running at 2.3GHz. Both are a little limited, so some upgrades will be made to the system.

4 SATA drive bays are located behind the magnetically-locked front door, there’s a 250GB boot disk in here along with a pair of 500GB disks in RAID1 to handle the website files & databases. For my online file hosting site, the server has a backend NFS link direct to Volantis – my 28TB storage server. This arrangement keeps the large file storage side of things off the web server disks & on a NAS, where it should be.

First thing is a RAM upgrade to the full supported capacity of 16GB. This being a Proliant server machine, doesn’t take anything of a standard flavour, it’s requirements are DDR3-10600E or DDR3-12800E (the E in here being ECC). This memory is both eye-wateringly expensive & difficult to find anywhere in stock. It’s much cheaper & easier to find the ECC Registered variety, but alas this isn’t compatible.

Over the past 48 hours or so, I’ve been migrating everything over to the new baby server, with a couple of associated teething problems, but everything seems to have gone well so far. The remaining job to get everything running as it should is an external mail relay – sending any kind of email from a dynamic IP / domestic ISP usually gets it spam binned by the big providers instantly, regardless of it actually being spam or not – more to come on that setup & configuring postfix to use an external SMTP relay server soon!

If anyone does find something weird going on with the blog, do let me know via the contact page or comments!

Posted on October 22, 2016October 21, 2016 by The Engineer — Leave a comment

Cheap eBay Molex-SATA Power Adaptors

To do some upgrades to my NAS, I needed some SATA power adaptors, to split the PSU out to the planned 16 disk drives. eBay has these for very little money, however there’s a good reason for them being cheap.

The marking on the wire tells me it’s 18AWG, which should be good for 9.5A at an absolute maximum. However these adaptors are extremely light.

Here’s the cheapo eBay wire compared to proper 18AWG wire. The cores in the eBay adaptor are tiny, I’d guess about 24AWG, only good for about 3A. As disk drives pull about 2A from the +12v rail on startup to spin the platters up to speed, this thin wire is going to cause quite the volt drop & possibly prevent the disk from operating correctly.

Posted on January 3, 2016 by The Engineer — 2 Comments

Roku LT Teardown

Here’s another retired piece of tech that we used to route media from the NAS to the main TV. It was retired since it’s inability to support XBMC/Kodi & having some crashing issues.

After attacking the case with the screwdriver (Torx in this case), the main board comes out. The CPU in this looks *very* familiar, being a PoP device. There are unpopulated places for an ethernet interface & USB port here.

After a little digging is turns out the CPU in this device is a BCM2835, with 256MB of RAM stacked on top. It’s a Raspberry Pi! Even the unpopulated part for Ethernet is the same SMSC LAN9512!
There’s 32MB of Flash for the software below the CPU.
On the far right of the board is a Broadcom BCM59002IML Mobile Power Management IC.

On the bottom of the PCB is the WiFi chipset, a Broadcom BCM4336, this most likely communicates with the CPU via SDIO. There’s also a section below for a Bluetooth chipset.

Posted on November 19, 2015March 27, 2017 by The Engineer — Leave a comment

Evening Musing – Linux RAID Rebuilding

My main bulk storage for the home LAN is a bank of 4TB drives, set up in a large RAID6 array. Due to a brownout this evening on the +12v supply for one of the disk banks, I’ve had to start rebuilding two of the disks.

The total array size is 28TB after parity – 9 4TB disks in total. The disks are connected through USB3 to the file server.

Here’s the current status of the array. Two of the disks decided that they wouldn’t rejoin the array, so they got their superblocks cleared & readded manually. This forced the array into rebuilding.

Rebuilding an array of this size takes a while, as can be seen from the image above, it’s going to take about 7200 minutes, or 5.2 days.

Posted on October 22, 2015 by The Engineer — Leave a comment

Netgear GS308 Gigabit Switch

Here’s a new addition to the network, mainly to replace the ancient Cisco Catalyst 3500 XL 100MB switch I’ve been using for many years, until I can find a decently priced second hand commercial gigabit switch.

Here’s the switch with some network connections on test. So far it’s very stable & draws minimum power. I’ve not yet attempted to run my core links (NAS) through yet, as I’ve not yet seen a consumer grade switch that can stand up to constant full load without crashing.

Here’s the switch with it’s lid popped. The magnetics can be seen at the back, next to the RJ-45 ports, the large IC in the centre is the main switching IC, with a heatsink bonded to the top. Very minimal design, with only a couple of switching regulators for power supply & not much else.

Here’s a closeup of some of the support components. There’s a 25MHz crystal providing a clock signal for the switch IC, just to the right of that is an EEPROM. I imagine this is storing the switch configuration & MAC address. Further right is one of the switching DC-DC converter ICs for power.

As a quick test, here’s 500GB of data being shifted through the switch, at quite an impressive rate. I’m clearly maxing out the bandwidth of the link here. Soon I will upgrade to a 10G Ethernet link between the NAS & main PC to get some more performance.

The Shack

So, here is where all the action happens.

Main radio of course is housed on the left, it’s partially hidden under my currently over-populated breadboard.

All 3 monitors are linked to the same PC, using a pair of video cards. This is a very flexible system with so much screen real estate.

Main system power is provided by the pair of power supplies next to the radio – these are homebrew units using surplus switched mode PSU boards. Check my previous posts for more details.

The main power supply system. These two supplies are cross connected, giving a total DC amperage of 30A at 13.8v. There is also a link to a large 220Ah lead-acid battery bank (orange cable), to keep me on the air during power outages. This cable is getting upgraded to something more beefy shortly. The white cable is currently supplying power to my online radiation monitor.
The main high-current DC outputs are the Speakon connectors next to the meters. The top one is powering the radio directly, the bottom is linked through to my 12v distribution box for lower current loads, such as the oscilloscope, audio amplifiers, tools, etc.

Attached to the side of the desk is the radiation monitor itself.

Under the radio is the core NAS of the network. It’s an array of 9 4TB disks, in RAID6, giving a total capacity after parity of 28TB. This provides storage & services to every other machine in the shack, the Raspberry Pi on top of the disk array is doing general network housekeeping & monitoring, also generating the graphs for the Radiation Monitor page. A Cisco 48-port switch is partially out of frame on the right, providing 100MB Ethernet to the devices that don’t require gigabit.

Posted on December 4, 2012March 27, 2017 by The Engineer — Leave a comment

Site Hosting

There have been quite a few updates to the hosting solution for this site, which is hosted locally in my house, from the above setup, in a small comms rack, to a new 22U half rack, with some hardware upgrades to come.

Core switch here has been removed, with the rest of the core network equipment. The site was kept online by a direct connection into the gateway to the intertubes.

New 22U rack, with the core switch, FC switch & management & monitoring server installed.

As I had no rack rails to start with, the servers were placed on the top of the rack to start off, here is the Dell PowerEdge 860 pfSense core router installed, with the initial switch wiring to get the internal core network back online. This machine load balances two connections for an aggregated bandwidth of 140MB/s downstream & 15MB/s upstream.
The tower server behind is the NAS unit that runs the backups of the main & auxiliary webservers.

Still with no rack kits, all the servers are placed on top of the rack, before final installation. This allows running of the network before the rest of the equipment was installed.

The main server & aux server are HP ProLiant DL380 G3 servers, with redundant network connections.

Still to arrive are the final rack kits for the servers & a set of HP BL20p Blade servers, which will be running the sites in the future.

Stay tuned for more updates as they happen!