rashbre central: June 2021

Wednesday 23 June 2021

Knock-on effect

[Technical alert - bypass this post if not interested in computer topics ] 

I use my computers for a variety of tasks like music, video, photography, authoring, plus the regular tasks that people get up to like email and browsing. No wonder I've accumulated some data over the years.

So I knew that the replacement of a large amount of my disk storage required a more detailed rethink of the rashbre LAN. Old mainframe systems used to have so-called batch runs which could take hours or sometimes days to run. I'm hoping to stay away from this for rashbre central.

The existing Drobo disk storage units have a one Gigabit ethernet connection, but the new Synology has 4 Gigabits. which can be bound together. That's an obvious thing to do, except I need (a) fast Category 8 LAN cabling (b) enough slots on my switch to be able to plug them all in. Yep, done - and with fancy coloured cabling too so I know which are the really fast links.

Then I have to think about the size of disks to be used. The Drobo units are set up with 5 times 6 Terabyte disks. I used to use a certain financial sum as the sweet spot for disks, but I now realise that 6 Tb is about the maximum I want to be copying around, at least until the rest of the infrastructure catches up.

It also means I can dip into my spare disk drives to start the population of the Synology unit.

Then I'll be interested in adding in a couple of RAID1 M.2 cache, which could speed the whole disk access to the device. They are like 2 mini-disks dedicated to caching the access to the device and using two means they are read-write RAID1 compliant 'fail-safe'.

Then, for the main disk units, I'm using the Synology SHR hybrid variety of RAID which allows a Drobo-like mix-and-match of drive sizes with less waste than a vanilla RAID configuration.

I've also got to think about 3-2-1 backup. That's the approach which says have 3 copies of data (the working data and 2 backup copies) on two different media (disk and tape) with one copy off-site for disaster recovery. Except tape is a bit old-fashioned and I'll have two variants on different disk formats.

That's where a Drobo can still be useful: to run the second backup, suitably off-site.

...And I realise that this is the type of post for which 'blogs' were originally invented!

Tuesday 22 June 2021

Another one bites the dust

It's finally time to replace the second of my Drobo 'Data Robotics' units. They are disk drive enclosures that support NAS functions. There's been various ways that they seem to go wrong.

  1. Power supply dies. It still switches on but doesn't deliver enough current to restart the whole set of drives. I've replaced power supplies and kept spares, but the connector type is different on different units, which adds to the pain.
  2. Drive dies. Inevitable that a drive would die from time to time. I have the Drobos set up with data redundancy so that one drive can fail but the system can continue to work, until I perform a hot swap.
  3. In a long-serving unit, the physical act of replacing the drive seems to disrupt the motherboard and then will signal perhaps a different error, which forces a more complex automated rebuild.

The first, say, five years seem to be okay, but after that period I wonder if the heat affects the motherboard in some way, reducing its reliability? My prior failed Drobo wouldn't restart at all , even after a new power supply unit was added and I took the number of drives down to one WD Red unit

So now I'm trying Synology instead. Some say that Synology are more complicated to get running, but I've found it pretty straightforward so far.

Saturday 12 June 2021

Ice creams on the beach

A fun thing about living in the West Country is seeing the local news coverage of the G7 talks. It's all about the Queen getting off the train at Saint Austell and Joe Biden eating an Ice Cream.

We've had odd looking planes buzzing overhead, even as far away as Topsham. A couple of very strange looking ones flew over in convoy as well as a few helicopters.


There's so many extra helper-people in Cornwall that they ran out of accommodation in St Ives, and had to hire a cruise ship to provide the extra beds. Now, some might know that there's a flotilla of empty (ghost) cruise ships all around Torbay at the moment. Admittedly it's around the coast from St Ives, but not a long journey. 


Cornwall Live reports that Governmental procurement swung into action and instead has hired extra beds from the Estonian firm Tallink who run cruises in the Baltic. MS Silja Europa has been procured to sleep 1,000 of the 6,500 security people present.


I think the old Beano word is 'spliffication'.