Re: [Tails-dev] Cleaning IUKs and updating disk space requir…

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Lähettäjä: sajolida
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Aihe: Re: [Tails-dev] Cleaning IUKs and updating disk space requirements for mirrors
sajolida:
> anonym:
>> sajolida:
>>> During the 2.12 release at least one of our mirrors run out of
>>> disk space. They followed our instructions closely and allocated 10
>>> GiB (we ask for "5-10 GiB") and apparently we're now a bit above 10
>>> GiB.
>>
>> Ouch! :/
>>
>>> I'd like to:
>>>
>>> 1. Make sure that we have a process set up to clean very old IUKs.
>>>
>>> For example, we could say that we only keep IUKs for the big
>>> version number. IUKs for 2.x until 3.0 is out as a change in the
>>> big version number will lead to no IUK for everybody. Right I see
>>> IUKs for 1.0~test on the mirrors which lead me to believe that
>>> there is only an ad-hoc process:
>>
>> The 1.0~test IUK is a dummy IUK used for automated testing. Please
>> ignore it! :)
>
> Ah!
>
>>> http://dl.amnesia.boum.org/tails/stable/iuk/
>>>
>>> I didn't check what the release process says about that.
>>
>> At the moment the process is to always remove IUKs that are older
>> than six months, and to remove ~alpha/~beta/~rc IUKs as soon as the
>> final release is out (except the IUKs upgrading from those versions
>> to the final one, of course).
>
> With this and the 1.0~test thingie, I understand better what I see on
> the mirrors and I'm happy that we already have a good process :)
>
>>> 2. Fix the current requirements which seems too low. Let's do a bit
>>> of calculation. Now is a quite epic time for mirrors with 12
>>> versions in the 2.x cycle and a heavy preparation for 3.0 so it a
>>> good time to adjust our requirements.
>>>
>>> - We're now publishing two IUKs per version (n-2→n and n-1→n) and
>>> they are 263 MiB on average. So for 12 versions and 6 RCs, that's
>>> 30 IUKs and 7.7 GiB.
>>
>> Remember, we provide IUKs from the previous two *planned* releases,
>> and any unplanned (i.e. emergency) releases in between, so the
>> *minimum* number of IUKs per version is two.
>>
>> Also, this number is higher than it should be because we clean up
>> IUKs every six months, not when Tails migrates to a new Debian
>> version. If someone feels like it they could come up with a new
>> number that takes that into account, and adds a few emergency
>> releases (incl. the extra IUKs that implies for the following
>> releases), but I'm happy with stating that 10 GiB seems enough.
>>
>>> - We have 3 IUKs for 3.0~betaX and will have at least 2 more
>>> (beta4→rc1 and rc1→3.0) and they are significantly bigger. That's
>>> 1.9 GiB. - We have 2 full ISO (2.12 and 3.0~beta4) and might have 3
>>> max if we include an RC. That's 3.0 GiB.
>>
>> Also, right around release n, both the n-1 and n ISOS will be on the
>> mirrors, so that should be more like 4 GiB.
>>
>>> So that's 12.6 GiB.
>>
>> Finally, this number doesn't take into account the project/vagrant
>> directory which currently is at 2 GiB, but OTOH we will soon be able
>> to remove it, so let's ignore it.
>>
>>> We shouldn't discard publishing even more IUKs in the future (I
>>> think anonym had some crazy plan about this somewhere).
>>
>> FWIW, with that vague, potential plan (#11131) it's expected that the
>> space needed for (stable) IUKs will increase to 11 GiB. But those
>> numbers are based on data for the 2.x series. With 3.x things can go
>> either way: in general, our ISO is growing so we can expect larger
>> IUKs; but 3.x will be reproducible, so we can expect IUKs to be
>> smaller. We'll see! :)
>>
>>> 3. Have more explicit requirements. Apparently not every mirror has
>>> good monitoring of their disk space, so putting a range as
>>> requirement could lead to more failures than setting a strict
>>> requirement. So what about updating our documentation to say
>>> something like:
>>>
>>> "You will also need 15 GiB of disk space maximum."
>>
>> Disk space is cheap! My expectation is that for those that can offer
>> to run a mirror, 15 GiB is nothing, and given your current
>> (incorrect) approximation I think we're asking for too little. I say,
>> let's go for 30 GiB, which I bet no mirror operator will mind
>> providing, and as a bonus I believe we'd be ready for the "crazy
>> plan" (#11131) in case we decide to go that way.
>
> Thanks for all the extra info! Summarizing your version we're talking about:
>
>   - Official ISO         2 GiB
>   - Official IUK        11 GiB
>   - Testing ISO             2 GiB
>   - Testing IUK             2 GiB

>
>   - TOTAL            17 GiB

>
> I also thought that we could assume that disk space is cheap but then I
> rememered how much money we actually spending on disks and that always
> freaks me out :) But right, mirror operators might not store all their
> stuff on SSD like we do.
>
> I'm also not super happy to ask for much more than what we need (right
> now three times more than what we use). But yeah, I guess that I'll bump
> the number to 30 GiB, write all mirror operators and see if that's an
> actual problem for some of them.


I asked them and nobody said it would be problematic. One answered that
20 GiB is a typical allocation for cheap VMs but that adding 10 extra
GiB is about $1 a month more.

So let's keep it like this.