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Ralsina.Me — Roberto Alsina's website

Owning a Pet Server, in 2022

Introduction

The slow­est pen­du­lum in tech is the dis­tri­bu­tion/­cen­tral­iza­tion one. It takes years, even decades to swing. That's why we once had cen­tral­ized time­shar­ing com­put­ers with dumb ter­mi­nal­s, and then we had per­son­al com­put­er­s, which we turned in­to in­ter­net ter­mi­nal­s, which we are stuck with.

This seems to be stick­ing, but hey, so did the oth­er two. It may swing the oth­er way, or it may not. Who knows, I am not a fu­tur­ol­o­gist, but I am swing­ing it a lit­tle bit, for my­self, in one small area: I am not hap­py with my da­ta liv­ing pri­mar­i­ly in large serv­er farms owned by oth­er­s.

So, rather than hav­ing my da­ta live in a cat­tle serv­er in a serv­er far­m, it now most­ly lives in a pet server, at home.

Al­low me to in­tro­duce you to ... pinky.

Picture of a small white plastic computer

Pinky will not wow you with spec­s, it's per­haps the slow­est prac­ti­cal serv­er pos­si­ble:

  • Rasp­ber­ry Pi 3b+, 1GB of RAM
  • 16GB SD card
  • 2x500GB HDD (mir­rored)

But it is more than enough for some spe­cif­ic class­es of work I need­ed. In this doc­u­ment I will try to ex­plain why I want­ed to do them, de­scribe them, and ex­plain the trade­offs in­volved, and the de­ci­sion process that lead me to the de­ci­sion to adopt this so­lu­tion.

Software

One of the most im­por­tant things here is Gitea.

It's hard to over­state what a game chang­er it is for a spe­cif­ic kind of user: Gitea makes host­ing a user-friend­ly git ser­vice easy and cheap.

So what? You may ask.

Well, a git serv­er is use­ful as a back­end for many ac­tu­al­ly use­ful ser­vices, even if you don't care about soft­ware de­vel­op­ment (which I do).

Pass

For ex­am­ple, sup­pose you want to man­age your own pass­word­s, in­stead of re­ly­ing on a third par­ty ser­vice. Well one way to do it is to use pass which is an open source im­ple­men­ta­tion which is sup­port­ed in most web browser­s, desk­top ap­pli­ca­tion­s, ter­mi­nals and what­not.

But if you have more than one de­vice ... then how do you sync your pass­words be­tween them? Yes, us­ing a git serv­er.

Chezmoi

Yes, I use more than one com­put­er. I have one at home, one in the of­fice, an­oth­er one for work, plus I am build­ing some home­made stuff us­ing rasp­ber­ry pis, and I want some things to work in the same way in all of them.

Chez­moi is an im­ple­men­ta­tion of the dot­files con­cep­t.

Ba­si­cal­ly: you tell it to man­age some of the con­fig files in your home di­rec­to­ry, which are then ver­sioned and shared be­tween com­put­ers us­ing ... you guessed it, a git serv­er.

It took some ef­fort to get things in a use­ful state but now I think it's ac­tu­al­ly adding val­ue to my sys­tem­s.

My Website

Yeah, I know, so 2003. But hey, it works for me. A cen­tral­ized lo­ca­tion for:

  • Things I write, like this one
  • Books I read and com­ment one, via goodreads
  • Videos I make, via youtube

Again, one of the goals is that my da­ta is mine so all those book list­s, and com­ments and star-rat­ings and what­ev­er ... why would they live on­ly in goodread­s? What if Ama­zon clos­es it?

Well, be­cause I can write soft­ware, I just get it all and put it in my own site, thank you very much.

And guess where the canon­i­cal source of all that is? Yeah, a git repos­i­to­ry, au­to­mat­i­cal­ly built and de­ployed.

Dis­clo­sure: my site is most­ly host­ed on a VPS I al­ready pay for, but there is a mir­ror at home­.ralsi­na.me which is, in­deed, in my pinky serv­er.

Gateway to my Office / Home VPN

All these ser­vices need to be ac­cessed from some­where. Us­ing some gen­er­ous free-ti­er ser­vices from fly and tailscale plus some con­fig­u­ra­tion ef­fort I can, from any of my com­put­ers (and my phone too) ac­cess any oth­er, re­gard­less of where they are, as long as they have some sort of in­ter­net con­nec­tion.

Hardware

Why THIS Hardware?

Be­cause I had it ly­ing around.

  • The rasp­ber­ry from old pro­ject­s, gath­er­ing dust.
  • Two 500GB HDDs from old note­books and giv­en as gift­s.

I had to buy 2 US­B-SA­TA ca­bles (about 5 dol­lars) and a nicer knit­ted mi­cro-usb an­gled ca­ble so it looked pret­ty (1 dol­lar).

Performance

Yes, it's pret­ty slow, but ... is it?

The rasp­ber­ry pi 3b+ is a 4-­core ma­chine, so it can run gitea, a web serv­er and a cou­ple oth­er things with­out any is­sues.

Sure, it's USB 2.0 on­ly, so ac­cess to stor­age is ... not fast.

OTO­H, most of the time I am ac­cess­ing ei­ther very small things (a git pull is pret­ty ef­fi­cien­t!) or over a slow link (30Mbps at most) so stor­age speed is hard­ly ev­er the bot­tle­neck.

One spe­cif­ic thing that makes no sense would be RAID mir­ror­ing be­tween the two disks, it would just make ev­ery­thing slow­er be­cause of the need to write each change twice.

So I turn off one of the disks (saves on wear) and turn it on at night to back­up the whole serv­er in­to it.

Adi­tion­al­ly, I can once a week take the sec­ondary disk and back it up off­site.

Power Usage

Run­ning at full throt­tle, my USB pow­er con­sump­tion mea­sur­ing thing I got for a dol­lar (so take it with a grain of salt) says it may use 1.1A at 5v, so in av­er­age it's prob­a­bly us­ing some­thing like 4W.

I checked my pow­er bill and that comes down to about 20 ar­gen­tini­an pe­sos a mon­th, or 10 US cents.

The Case

I grabbed a rasp­ber­ry "sleeve" case and a 2.5" HDD "sleeve" case out of thin­gi­verse, and slapped them on­to a few box­es, then print­ed it in the cheap­est 3D print­er mon­ey can buy. It works great.

Be­cause it's a Pi 3 and not a Pi 4 it can be pas­sive­ly cooled with no prob­lem and I print­ed the HDD sleeves at 50% in­fill so they would muf­fle the noise a bit. I can on­ly hear the oc­ca­sion­al click from the hard drives, but it's pret­ty much silen­t.

It's al­so around 10cm in each di­men­sion. That's pret­ty smal­l.

Conclusion

This serv­er (with­out the case, that's new) has been work­ing for around a month. It has au­to­mat­ic soft­ware up­dates for ev­ery­thing and if some­thing would hap­pen to break I can live with­out it for a few days with­out any is­sues.

I con­sid­er it a com­plete suc­cess.


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