Raid1 and JBODs or alternatives

I have a lot of old hard drives laying around as well as a Raspi and some PC parts. The drives are all different sizes speeds etc. – Id likes to set up a Raid where any drive can fail and can be exchanged. The bigger Drives should be fully used and every piece of data should be mirrored on another drive. For example, if I have a 1TB Drive and 2 500GB Drives id like to store data on the 1TB Drive and mirror it on either 500GB Harddrive so all 3 Drives are used as good as possible. I have 9 drives of different Sizes. Can I set up my Raspi or any other System (what Software should I use) that I can Setup a RAID and what RAID Level would that be? Also is there any Software I can use that when a drive fails I can just Plugin new Drives and the Data will be copied onto them until everything is mirrored again and that has no problem with temporary storage without mirroring for example when one of the big drives fails and I haven’t plugged in enough storage to compensate it yet?

The most intuitive way seems to be that i create two JBOD Volumes with the or almost the same size and run them in RAID1. Is there Software or better Ideas to get this going?

Alternatives to 2nd Line

2nd Line is an app which lets you have another phone number. With a disposable email, it may be possible to stay anonymous and have a number to ,say, prank friends or just register on random sites whatever you wish. Please do share such services. I am just goofing around to see what exploits can be used online.

Alternatives to directly connected networks for representing frequently-updated graphs

What are the relative merits of the various graph representations, such as adjacency matrix, edge list, adjacency list, directly connected network etc. Given that this graph will be frequently updated, split, joined to other graphs?

Business Context: I am writing a molecule editor in C# and have currently used a directly connected network, although this has proven to present problems when updating. I am looking for a better way of doing this.

PayPal alternatives for high-risk businesses

Lots of merchants choose PayPal as the only payment solution for business, and this is the root of their troubles. One of the reasons, in particular, why PayPal has such a brilliant reputation is that it works mostly with low-risk businesses. They really are playing it safe not willing to take on risks associated with high-risk merchants.

PayPal alternatives for high-risk businesses

What alternatives are there for “magic” bluetooth keyboard and mouse?

I gave a try to “standard” Apple’s Magic Mouse and Magic Keyboard with Numpad.

Oh, that was huge mistake (but “never try never know” of course). I strongly dislike both but most of my hate goes to mouse, probably: it is too sensitive and scrolls by itself sometimes. The keyboard is also pretty nonsensical:

  • key presses are too short (not that short as on “famouse” post-2015 models, but anyways I feel like it’s not enough for being comfort)
  • key captions are not that contrast (something gray) — very not clever given that they didn’t provide any built-in luminousity contrary to laptop’s
  • on letters key they used CAPITALS although it’s pretty typical QWERTY so hints aren’t needed much
    • but on others keys like [+], [-] of numpad + all those [Fn]s they decided to use small glyphs instead — I ended up using permanent markers to fix some of them

It’s very surprising how Apple makes blunders on some basic devices and this makes me look for alternatives. Hopefully I’ll change it to somewhat better.

Alternatives to get from Belize international airport to Belize City

I know there are taxis to the city by 25 USD but think I could walk the Airport Road to the Northern Hwy (about 3 km) to get a (cheaper) bus to Belice City so I can take the ferry to the islands. Is that possible? I have seen on Google Maps some bus stops in the nearings but I want to be sure before walking near 2 miles and still after all needing to get a Taxi.

Thank you all

Are there any well known alternatives to the SOLID principles for OO programming?

I´m looking for some kind of better compilation of principles which takes the old basic concepts (DRY, KISS, etc…) and applies them to OOP related concepts like abstract clasess, interfaces etc…

Some reasoning behind this quest:

I find some interpretations of the SOLID principles very compelling, but I’ve found so diverse interpretations of these principles on the web that I find them close to useless. The idea of a software design principle IMHO, is to provide a base framework for developers to discuss software development best practices. But when the advocators can’t even agree on what their principles mean, it’s time to look for alternatives.

I also have found that people trying to follow these principles create extremely over-modularized architectures mostly because they decompose simple implementations into even smaller modules, disperse over the project which makes it close to imposible to discern the purpose of these micro-modules in the context of the whole project.

Summarizing, I just want to know if there is any other well known name for a different group of OOP principles that are more tied to the old basic KISS, DRY, etc…

IoT: Alternatives to MQTT Proxy for Kafka

I’m currently working on the development of a kind of tracking system.

Vehicle will embed an IoT device that will transmit their position via NB-IoT, after some research it seems that it will be better to use the protocol MQTT instead of simple HTTP Get/Post.

The current stack of the application is Spring Boot, Eureka, Zuul and Kafka.

So I wanted to send directly the message from the devices to Kafka and one solution I saw is Confluent MQTT Proxy for Kafka.

But problem this is part of a commercial platform and I would prefer stick to Open Source components. So is there any open source alternative ? (it’s also a question of cost as we are in a pilot phase at the moment)

or should I start to develop my own proxy? Obviously I would prefer to avoid that but in case, if someone has information about how this proxy is working

Any advice or idea would be appreciated.


Arrayformula and Sum queries. Possible alternatives

I am using a sheet to list and summarise teachers absences and substitutions. Here’s the worksheet

Basically in the sheet “Substitutions” all absences and substituions are stored record by record:

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The “Summary” Sheet summarises absences and substitutions by teacher:

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Summarising is done by month using the following formula:

=iferror(query(Substitutions!$  A$  3:$  H$  21;"select sum (E) where( (H) = 'M' AND month(B) = " & month(F$  3)-1 & " AND (A) =  '" & $  A6 & "' AND (C) = 'ASS') label Sum (E)''"))/1440 

As this calculation is done cell by cell and row by row (columns F to N), I’d like to use arrayformula to replicate the same formula across the rows, however it looks like arrayformula doesn’t expand properly “sum” in queries.

How can I modify the above formula to be used with arrayformula?