What are the .dtb and .elf files in /boot partition in raspbian?

Hi @Fabby. How goes it?

@Biswapriyo .dtb is device tree stuff (see maybe en.wikipedia.org/wiki/Device_tree)

@Biswapriyo the elf files are firmware. raspberrypi.org/documentation/configuration/boot_folder.md actually describes all the stuff (first result on Google for start_cd.elf)

@FaheemMitha btw, I submitted ABAN to alternativeto.net alternativeto.net/software/aban ... I wonder if anyone but me has used it yet :-/

@Fabby I wish you luck on your job search. Just started on mine in earnest recently, after my employer closed :-(

@ThomasWard I sent my résumé to Canonical to work on Ubuntu, no idea what they'll say since I don't really have that much involvement directly with Ubuntu. Though of course I appreciate any positive words :-)

@derobert i have no say in the matter ;P

I don't have any sway at Canonical's level

Well, then, no 10TB NVMe drives from me! :-D Of course, they're well outside the price range of unemployed folks anyway, so...

@derobert Maybe someone will. BTW, I'm not sure if you were expecting a response to your post on that issue.

@derobert Have you tried Dropbox yet?

@FaheemMitha Trolling for upvotes to get it higher on the list of DBAN alternatives, of course.

@derobert Huh?

alternativeto.net (no idea if you're familiar with the site) lets you look for alternative apps. They're sorted based on users voting for them, so e.g., if you look up DBAN there, and scroll way to the bottom, ABAN shows up. To get it higher, it needs votes :-)

Dropbox seems to have most all its positions in CA

@derobert I see.

@derobert Yes, that would be my guess. Are these orgs usually open to remote working?>

Some are, some aren't. I didn't see anything about it in their job postings, so I'm guessing no.

Normally places that are advertise it.

@derobert I see. Good to know.

I guess if you were a really good match you can always ask.

If you don't mind me asking, who did you work for before your current employer?

I did a bunch of contracting with a ton of people... let me just send you my résumé.

@derobert Ok.

Sent

@derobert Thank you.

Did you write your resume using TeX? It doesn't look like it, but it's hard to be sure.

No, on second thoughts it might be TeX.

No, that's from LibreOffice. I can send that file if you want

I used LibreOffice because its easier to export to Word for all the crazy people who want that.

I sent it. Will take a second as its much bigger than the PDF (full font embedded)

@derobert Yes, I see.

... better for what?

Drivepooling

Could you elaborate a little?

Nas

I have 4 * 8tb HDD that I wanta use as a back up drive

And I have 4 * 6tb I wanta use as normal day storge

For my nas

Then I'd use neither of those, I'd use mdraid and/or LVM. Or even btrfs.

What's the difference

Could you explain more I am new to this

I only know of ZFS

ZFS is another good option

Yeah but don't work that great on linux that well

And for my backup I wanta something low

That couldn't really be corruptable

The various union filesystems are for stacking filesystems on top of each other. I.e., you have file set A, and you want to override some of the files in A with files in B.

Was was planning on using snapraid to backup

For the linux install for an file server would you put any root subdir on a different partiton?

I haven't used SnapRAID, but quickly looking at their home page, it sounds like it wants just a bunch of disks and manages redundancy itself

JBOD for backups

I wouldn't trust raid for it

RAID on backups is pretty common and reasonable. You build a RAID array, put a filesystem on it, and make copies of the data to that filesystem. (Which is different than trying to treat RAID as a backup, which it's not).

Iwould have two sets of drives

The rpoblem with raid is it nots explainable

Which sucks

Anyway, it sounds like for SnapRAID you just want to set up your 4×8TB as just ext4; and I'd set up the 6×6TB as some form of RAID, possibly through LVM.

@MathCubes Not explainable?

Expendable

Yeah

do you mean expandable? As in you can add more disks/larger disks?

@derobert Your resume generally looks good, but you are missing any mention of kind of desired employment.

Yes

More disk if I ever need it

No

Just for home

One user me

I already have them

How can I recover an raid if my os get corrupted?

Linux mdraid can add disks and larger disks on most RAID levels. LVM-RAID can really do it (and uses mdraid under the hood).

Also my mobo for some reason don't support raid

It's only like on 3 out of the 6 sata ports

I don't know why but I can't change it

mdraid is done by Linux in software, no mobo support is required.

Great

Is there an supid Web interface I must use like OVM for it

And unless you have a really high-end (think server) board, it doesn't really have RAID support. Just some other, likely less reliable, software RAID.

@MathCubes No, you can entirely manage it with the CLI.

I can't stand that. Using another PC

Great

Love that

I can just SSH in

@MathCubes Yes, mdadm is normally recoverable. From a Linux live CD/USB stick, for example

That's wounderfun

How can I backup the raid config files? By the way, thanks for the help

The RAID config is stored on each drive, you can use mdadm --examine to see it (and save a copy of it)

Great

For LVM-RAID (which is much more flexible, but also more complicated) its also stored on the drives, with a backup in /etc/lvm which you can copy somewhere off the RAID set.

So it's not like I lose the OS I lose my data

What would you recommand

No, you can take the drives to any reasonably recent Linux machine and use them

?

If you lose the OS somehow, any Linux machine will be able to read them. Provided its an Linux install that's less than say 10 years old. A live CD/USB works well.

With an nas how frequent do you have to replace the HDDs?

Every 3 years or so?

If an hdd is like 2years old but you never really use it would it last for another 3 years or does it only have an year of life left?

When they fail (as quickly as possible), and when you need more space (which you can plan for)

k

I think 5–7 years is a reasonable guess for HDD lifespan nowadays, provided they're treated well. That's of operation.

I have Wd golds

That are like an year old but I haven't really use them yet

You have redundancy so that if one fails, you just replace it. Except for failed ones, normally you wind up replacing them because you want larger ones, not because they're old, at least that's my experience at home.

Well yeah

What sucks is the case is like too small for them so the top of them touches the top of the bay

And like one of the sliever stickers came off so I had to replace it

No big deal

I just put an plasic cover on them

To prvent phsyical damage to them by the case

Make sure you have adequate cooling. I'd consider fixing the case.... You can normally check the drive temperature via SMART (e.g., with smartctl). Running them very hot will reduce their lifespan.

I cna't fix it

I contacted the manufactur of it

THey sent new bays same issue

It's BS

4 is a somewhat inconvenient number of drives. I'd personally go RAID-6 on it (meaning you'd get the capacity of 2 drives and be protected from up to two failing), but I'm paranoid. RAID-5 would give you another drive of capacity, but at greater risk of failure

I have 4 hdds

I gonta have one reduancy

@derobert are source code available for those files?

@Biswapriyo Probably at least the device tree ones, not sure about all of the firmware.

@MathCubes RAID-5 protects against one disk failing. The problem is then if while rebuilding another disk fails (very bad, you then have 2 failed disks), or if you find out you had an undetected bad sector on one of the remaining disk (lose whatever data was on that sector). Hence why I go with RAID-6, to protect against those, as long as I promptly replace the first failed disk.

That's why I going to have an backup

of 4 disks

ANyways

I am going to take a shower Be back in like 20-30 min

I use more than 6tb already

12 tb isn't going to be enough

Right, just beware that if you have to restore 14TB from backup... that's going to take a while. Over a day if you manage 150MB/sec, which you could only do if both copies are in the same NAS, or you have something faster than gigabit connecting them.

@FaheemMitha Yeah, I haven't really figured that one out. I think what I did at Metrics sort of gets called devops nowadays...

@derobert It's probably worth adding a few lines indicating your preferences, if any.

@MathCubes BTW, you should read up on these things before using them. And, also, mdadm --create is used only for creating new, empty RAID arrays. It can, in the hands of an expert, be used as a last-ditch recovery attempt... but it's almost always the wrong answer. (For some reason people show up here having made the situation worse with it, and only then ask experts here for help. Don't do that!)

In academia, people expect to work on things that interest them.

I realise it's a bit different out in the big world.

I thought in academia people expect to work on begging funding agencies for funding :-/

@derobert That too. But in the spare time left over from begging, they expect to work on things that interest them.

That supposedly makes it worth while.

back

Now

@derobert If you are still on what do you recommand me to do with this?

I don't really have the time I am in medic school

mdraid + filesystem on top is the most simple (so least reading). LVM-RAID adds nice features (like different parts using different RAID levels, easier to expand, disks of different sizes, etc.) but is a lot more reading.

So it sounds like you should just stick with the first one.

K

Do you think I should keep the 6 tb hdds and 8tb hdds apart

Or is there away to put 2 together? 2 6tb and 2 8tb

?

Going to watch this

A backup is always a good idea. RAID is always easier with drives of the same capacity.

k

BTW: LVM does a lot of stuff. That video will probably only cover the traditional stuff, which is combining drives and splitting them (like partitions). You can run that on top of mdraid too, which will likely be mentioned. LVM-RAID is much newer, not sure if there are good videos. You can read the manpage though at e.g., manpages.debian.org/unstable/lvm2/lvmraid.7.en.html

k

@derobert I don't know about you, and I know this is a bit off topic, is that with alot of cases they don't even include enough space in the back of the case. I have broken off sata connections on hdds before trying to get the panel on the case.

Like why do they do that, I wounder

The good news is you can just ignore the parts of LVM you don't use. (Because I don't want to think about how long a video that explained all of LVM would be. Many hours.)

It's so freaking supid

@MathCubes Maybe you need right-angle SATA connectors?

Same issue

Anyways

I've never had this issue. Of course, I've not used home NAS enclosures. Only PC cases and server-class stuff with backplanes, etc.

I am going too look up LVM

I mean with PC causes

*cases

I've had some PC cases do evil things like if you want to take out a hard drive, first unmount the CPU fan (or rather, bend the bloody case so you don't have to). But drives are at the front... I've never had an issue with the back of the case not fitting on. Right-angle connectors hardly add any depth to the drive. I can only suggest buy better cases :-(

lol

I'm sort of curious if you have a picture of this monstrosity.

Yeah

Laptops are even worse

Sure, laptops, but those have serious size constraints. Could you post a picture? I want to see this...

I hate all of them. I like the idea but what the manufacturers do is absolutely BS

Like no standard at all

All proprietary

@MathCubes yeah, laptops can be like that for a lot of parts. Silly size and weight constraints. Desktops though usually aren't.

alias LEEEEEEEROOOOOOOOYYYYY-JENKINS="printf '%s\n' 'Good morning and salutations fine gentlefolk'"
LEEEEEEEROOOOOOOOYYYYY-JENKINS >/dev/chat

I am neither fine nor gentle

I don't know what LEEEEEEEROOOOOOOOYYYYY-JENKINS is

$ type LEEEEEEEROOOOOOOOYYYYY-JENKINS
LEEEEEEEROOOOOOOOYYYYY-JENKINS is aliased to `printf '%s\n' 'Good morning and salutations fine gentlefolk''

I am planning to learn some javascript frameworks sometime. Not sure which one(s) to choose

Javascript is a gentle language

frontend: angular, React, Vue

backend: express

which of them?

nodejs

stat js ... /me wants to find out about inodejs

@StackExchangeforAll Nobody knows what that means. it's just something that Jesse likes to say.

wat up @FaheemMitha

Hi Jesse.

@FaheemMitha Google probably knows (at least after removing the emphasized extra letters).

I only knew it is some body's name in a video game. I have never had luck to play any video game, however

Before googling, I thought it was something related to Jenkins CI

I also hope to learn about it sometime

@derobert It's probably better if one does not ask.

I can turn on all the faucets in my house

nice vscode has an extension that does syntax highlighting for awk

Talking about syntax highlighting... I've just noticed that the nvi from ports on OpenBSD hase support for UTF-8, while the base system's vi doesn't. This means I'm nowadays using nvi rather than vim. export EDITOR=ed VISUAL=nvi

I used command lines for making some .NET Core app/api work in Linux

emacs for editing source code

I am reading about Flask for gaining another perspective for learning web app/service

frontend is still a blank to me

I used emacs's Java mode for C# code. It seems to highlight the syntax okay.

I am hoping to figure out the following patterns: command, mediator, which I saw in a Clean Architecture template

These are some of the things that I hope to do sometime. But I may forget

my work is exceptional

@jesse_b you should try perl, then when you catch the exceptions your work is death-defying.

@derobert I read "perl in a nutshell" a while back and was messing with perl during that but I stopped using it and now feel like I don't know it at all

die is how you raise an exception in perl (unless you're using a module which adds more feature/better syntax/etc.)

really should have been titled "perl in an oyster shell"

@jesse_b That's sort of what happened with me and Python. And somewhat, Ruby (though I did actually use Ruby for a while, but have mostly forgotten since its been a bit)

@jesse_b LOL, yeah. That would have been a great title.

I only have one lunch packed for today :(

Do you normally pack multiple lunches and hide them around the building, in case several are stolen?

@derobert I normally eat an early lunch and a late lunch

Uh-oh, you might have to find a restaurant.

My office keeps some snacks in it, I'll just eat some beef jerky and peanuts or something

trying to get to 215 lbs before spring

... normally having fewer lunches helps with that. Unless you're one of those odd people trying to apply += to weight, not -=.

Yeah, I'm currently around 202-205

and I'm definitely an odd person ;)

Well, I'd suggest French fries, but I'm guessing you're looking for muscle, not just weight :-P

Yeah, most people actually recommend 1 gram of protein per pound of body weight if you are weightlifting which seems almost unobtainable for me. I have a hard time forcing myself to eat that much

@jesse_b 16 oz sirloin?

@derobert yeah I probably eat more red meat than I should :p

Hah, that 16 oz sirloin should get you somewhere around 200g protein

I guess I actually come closer than I thought, I'm eating two chicken thighs right now which according to google should be around 64g of protein

yeah, meat has tons

since meat is basically water, protein, and fat

I am hungry

If I may say, 200+ lbs is twice of some other's weight

@StackExchangeforAll Yeah mostly children though

I can eat your lunches for a week

@StackExchangeforAll But then what would I eat?

Just eat what you like. Sorry, I didn't mean to offend you

Don't worry I am not easily offended =)

If eating gaining muscle and weight make you feel good, then go for it.

I'm eating a big slice of chocolate cake now

I am going to eat some green beans for the rest of the day

a can of green beans expired in Dec

where do you live Tim, if you don't mind saying

I don't, but I don't know whether it is good to say

foo

bar

do you live on your own?

What a big rain!

north ;)

surprising.

Can I do something like if ( n != 1 && f == 0 ) in c?

I guess so

@jesse_b Yes

Nice

I wrote a c program more complicated than hello world :)

gist.github.com/1f70b09ee949a01fa0fa5585badb3768

only gets one warning when compiling :p

@jesse_b #include <stdlib.h> ought to fix that

It does, thanks :)

BTW, the man pages normally tell you the headers you need. So man atoi will tell you.

@derobert Thanks

Just trying to pass time on a slow saturday :p

Of course, you might want to check argc before presuming argv[1]

blastpheme

	if ( argc < 2 ) {
		printf("oi! Provide a damn argument!\n");
		return 1;
	}

@jesse_b ./prime "I'm sure if you check Leviticus, Numbers, and Deuteronomy, you'll find plenty of reasons you're damned" .... is that a damn argument (though, admittedly a lazy and not very good one)?

LGTM

returns 0

yeah, probably does

I attempted to check if the argument is an integer but C is for wizards and I'm not that worried about it

You can use strtol for that. If you care.

(I guess them maybe I'd have to try ./prime 666, not sure what other damn arguments are also numbers)

asciinema.org/a/l9MwTTgWSGm02niyGUPKyrKQm

BTW, C variables can be more than one character long, as long as I'm being a cheeky bastard :-P

Yeah but why?

I haven't run out of alphabet yet :p

True, you haven't. Especially since its case-sensitive!

C is particular about it's ; line endings

I prefer being a bit more sloppy

Yes, quite a bit. It mostly ignores newlines, depending entirely on ; except for the preprocessor

Is there a c library (I'm sure there is) that handles argument processing?

man 3 getopt

I'm slow

getopt (and friends) are what C programs normally use for command-line argument processing.

gnu.org/software/libc/manual/html_node/Example-of-Getopt.html gives example code

I'm looking at that. Why is everything declared as an int, how is c an int if it's possible values are a, b, and c?

C treats single characters as numbers. E.g., on an ASCII system, 'A' == 65

(╯°□°）╯︵ ┻━┻

I'm starting to remember why I gave up learning C

Sometimes its an int instead of a char so that there is an invalid value (-1, typically) to use for an error. E.g., fgetc does this.

Other times its historical. int used to be the default type.

char is an integer type, like short, int, long, long long, etc.

can a single argument have multiple options?

@jesse_b yeah, that's normally allowed. E.g., 'rm -Rf' has both -R and -f in one argument

well I mean more like ./prime -r 1 100

getopt_long might be able to do that.

actually... you can do it with normal getopt. You just increment argv more. probably, haven't tried.

Normally you'd use two arguments, e.g., -s 1 -e 100

I'm going to just keep doing things with bash that people say I shouldn't use bash for

bash's getopt is similar :-P

how do I print an int as an ascii character

arguments.c:25:68: warning: format specifies type 'char *' but the argument has type 'int' [-Wformat]
                                fprintf(stderr, "You coming at me sideways?\nWtf is \`%s'?\n", optopt);
                                                                                      ~~       ^~~~~~
                                                                                      %d

(If I change it to %d it prints a number)

@jesse_b %c

@MichaelHomer Nice, thanks

@FaheemMitha As long as I don't have a job: don't ask...

>:-) ;-)

I'm just a busy bee and you can only look for a job about 4h/ day

E.G. I'm reading the UEFI spec and I'm reading systemd.timer

@derobert Urgh! The worst way to lose your job: no payout.

Well,... Maybe 3rd worst:

after gross misconduct and not being hired after your probation period.

But it's still up there!

I perform gross misconduct pretty much daily and I've never been fired for it yet

@jesse_b One of my ex-companies tried to fire me for gross misconduct, but I took them to court.

The C code I was just working on is incredibly gross and behaved in a completely unacceptable manor

It was their MO until I did that...

>:-)

@jesse_b :D :D :D

Good one!

@Fabby What did they accuse you of?

In that case: in a previous job as a Project Manager, I behaved grossly every day as well by cutting corners...

... but I opened "Technical debt" projects to clean up my own shit though...

@jesse_b Do you have Telegram?

@Fabby I do not. I try to stay away from the dark web

@jesse_b It's so good it's prohibited in Russia.

Whereas WhatsApp is not.

I know, I used to host them :)

@jesse_b Holy crap moly!

well not me personally

@jesse_b Well, I' wouldn't mind telling you in a private chat, but not publicly as it's kinda funny and just a little gross (depending on your POV)

@jesse_b I geddit.

(you used to work for a company that hosted them)

No worries

I'd definitely get the poor overworked mods all over me.

@jesse_b Let's keep it to "It might have been indecent to some stuck up VP, but definitely not gross to a Unix admin".

>:-) ;-)

When I was in the military I got fired from a position for slapping another man on the ass