Rancilio Silvia Upgrade

Weekend upgrades to my Ranchilio Silvia v4 espresso machine. Added a digital PID kit for improved temperature control Replaced the boiler element Thermal insulation Basic “smart” power control with Siri integration Upgrade the standard Ranchilio basket to a VST 18g Ridged Rebuild Photos Note the damage to the boiler elements terminals, this was shorting and causing the houses RCD to trip Wiring the PID controller Replacing the boiler thermostat with one connected to the PID controller...

July 11, 2021 · 1 min · 83 words · Sam McLeod

Flash Storage and SSD Failure Rate Update (March 2018)

It was almost 3 years ago that my open source storage project went into production. In that time it’s been running 24/7 serving as highly available solid state storage for hundreds of VMs and several virtualisation clusters across our two main sites. I’m happy to report that the clusters have been operating very successfully since their conception. Since moving away from proprietary ‘black box’ vendor SANs, we haven’t had a single SAN issue, storage outage....

March 20, 2018 · 2 min · 326 words · Sam McLeod

HP 4951C Protocol Analyser

My good friend Joel Shea received a most unlikely gift this Christmas - A vintage HP 4951 Protocol Analyser. According to the HP Computer Museum: Original Price: $3595 The 4951B was replaced by the 4951C and 4952A in 1986. Both new models handled Async, BSC, SDLC, HDLC, X.25 and SNA protocols. The 4951C also handled DDCMP, while the 4952A did not. The 4952A handled X.21 while the 4951C did not. Both new analysers used a floppy dive (618 KB) for removable media....

December 27, 2017 · 1 min · 91 words · Sam McLeod

Broadcom, Or How I Learned To Start Worrying And Drop The Packet

Earlier this week we started the process to upgrade one of our hypervisor compute clusters when we encountered a rather painful bug with HP’s Broadcom NIC chipsets. We were part way through a routine rolling pool upgrade of our hypervisor (XenServer) cluster when we observed unexpected and intermittent loss of connectivity between several VMs, then entire XenServer hosts. The problems appeared to impact hosts that hadn’t yet upgraded to XenServer 7....

October 13, 2017 · 6 min · 1240 words · Sam McLeod

The State of Android in 2016 & The OnePlus 3 Phone

I wanted to try Android for a couple of weeks, I like staying on top of technology, gadgets and making sure I never become a blind ‘zealot’ for any platform or brand. The OnePlus 3 I did a lot of research and decided to try the “Oneplus 3” as it was good bang-for-buck, ran the latest software had plenty of grunt with the latest 8 core, high clock speed Qualcomm processor coupled with 6GB of DDR4 - the specs really are very impressive, especially for a $400USD phone....

July 11, 2016 · 4 min · 721 words · Sam McLeod

Update Delayed Serial STONITH Design

note: This is a follow up post from 2015-07-21-rcd-stonith A Linux Cluster Base STONITH provider for use with modern Pacemaker clusters This has since been accepted and merged into Fedora’s code base and as such will make it’s way to RHEL. Source Code: Github Diptrace CAD Design: Github I have open sourced the CAD circuit design and made this available within this repo under CAD Design and Schematics Related RedHat Bug: https://bugzilla....

July 4, 2016 · 2 min · 217 words · Sam McLeod

SAN Intro

October 7, 2015 · 0 min · 0 words · Sam McLeod

SSD Storage - Two Months In Production

Over the last two months I’ve been running selected IO intensive servers off the the SSD storage cluster, these hosts include (among others) our: Primary Puppetmaster Gitlab server Redmine app and database servers Nagios servers Several Docker database host servers Reliability We haven’t had any software or hardware failures since commissioning the storage units. During this time we have had 3 disk failures on our HP StoreVirtual SANs that have required us to call the supporting vendor and replace failed disks....

September 13, 2015 · 2 min · 376 words · Sam McLeod

iSCSI Benchmarking

The following are benchmarks from our testings of our iSCSI SSD storage. 67,300 read IOP/s on a VM on iSCSI (Disk -> LVM -> MDADM -> DRBD -> iSCSI target -> Network -> XenServer iSCSI Client -> VM) Per VM and scales to 1,000,000 IOP/s total root@dev-samm:/mnt/pmt1 128 # fio --randrepeat=1 --ioengine=libaio --direct=1 --gtod_reduce=1 --name=test --filename=test --bs=4k --iodepth=128 --size=2G --readwrite=read test: (g=0): rw=read, bs=4K-4K/4K-4K, ioengine=libaio, iodepth=128 2.0.8 Starting 1 process bs: 1 (f=1): [R] [55....

July 24, 2015 · 3 min · 456 words · Sam McLeod

Delayed Serial STONITH

A modified version of John Sutton’s rcd_serial cable coupled with our Supermicro reset switch hijacker: This works with the rcd_serial fence agent plugin. Reasons rcd_serial makes for a very good STONITH mechanism: It has no dependency on power state. It has no dependency on network state. It has no dependency on node operational state. It has no dependency on external hardware. It costs less that $5 + time to build. It is incredibly simple and reliable....

July 21, 2015 · 3 min · 450 words · Sam McLeod

Video - Cluster Failover Performance Demo

July 12, 2015 · 0 min · 0 words · Sam McLeod

SSD Storage Cluster - Update and Diagram

Due to several recent events beyond my control I’m a bit behind on the project - hence the lack of updates which I apologise for. The goods news is that I’m back working to finish off the clusters and I’m happy to report that all is going to plan. Here is the final digram of the two-node cluster design: Plain text version available here This was generated from the LCMC tool (beware - it’s java!...

June 17, 2015 · 1 min · 79 words · Sam McLeod

Video - Storage Cluster Failover Demo

A brief demonstration of the failover and recovery process on the storage clusters I’ve been building.

May 14, 2015 · 1 min · 16 words · Sam McLeod

Talk - High Performance Software Defined Storage

A high level talk from Infracoders Melbourne on 12/04/2015. There’s also a low quality recording available here: Related posts: Building a high performance SSD SAN - Part 1

April 15, 2015 · 1 min · 28 words · Sam McLeod

Building a high performance SSD SAN - Part 1

Over the coming month I will be architecting, building and testing a modular, high performance SSD-only storage solution. I’ll be documenting my progress / findings along the way and open sourcing all the information as a public guide. With recent price drops and durability improvements in solid state storage now is better time than any to ditch those old magnets. Modular server manufacturers such as SuperMicro have spent large on R&D thanks to the ever growing requirements from cloud vendors that utilise their hardware....

February 16, 2015 · 8 min · 1590 words · Sam McLeod

Direct-Attach SSD Storage - Performance & Comparisons

Further to my earlier post on XenServer storage performance with regards to directly attaching storage from the host, I have been analysing the performance of various SSD storage options. I have attached a HP DS2220sb storage blade to an existing server blade and compared performance with 4 and 6 SSD RAID-10 to our existing iSCSI SANs. While the P420i RAID controller in the DS2220sb is clearly saturated and unable to provide throughput much over 1,100MB/s - the IOP/s available to PostgreSQL are still a very considerably performance improvement over our P4530 SAN - in fact, 6 SSD’s result in a 39....

February 15, 2015 · 1 min · 110 words · Sam McLeod

XenServer, SSDs & VM Storage Performance

Intro At Infoxchange we use XenServer as our Virtualisation of choice. There are many reasons for this including: Open Source. Offers greater performance than VMware. Affordability (it’s free unless you purchase support). Proven backend Xen is very reliable. Reliable cross-host migrations of VMs. The XenCentre client, (although having to run in a Windows VM) is quick and simple to use. Upgrades and patches have proven to be more reliable than VMware....

February 15, 2015 · 5 min · 970 words · Sam McLeod