Re: using Google Cloud for virtual tapes

"Stefan G. Weichinger" <[email protected]> Fri, 3 Jun 2022 09:13:13 +0200
Newsgroups gmane.comp.archivers.amanda.user
Message-ID <[email protected]>
Am 05.04.22 um 11:55 schrieb Stefan G. Weichinger:
> Am 04.04.22 um 23:33 schrieb Chris Hassell:
>> Google cloud works and works well enough indeed.   All of them work... 
>> but a non-block technique is capped at 5TB by almost all providers, 
>> and getting to there is complicated and can DOUBLE your storage cost 
>> over one month [only] if you cannot make temporaries without being 
>> charged.  (looking at you, Wasabi!!).
>>
>> However either A or B or C for Google specifically...
>> A) the desired block size must be kept automatically small (it varies 
>> but ~40MB or smaller buffer or so for a 4GB system) ... and each DLE 
>> "tape" must be limited in size
>> B) the biggest block size can be used to store 5TB objects [max == 
>> 512MB] but the curl buffers will take ~2.5GB and must be hardcoded 
>> [currently] in the build.  Its too much for many systems.
>> C) the biggest block size can be used but google cannot FAIL EVEN ONCE 
>> ... or the cloud upload cannot be restarted and the DLE fails 
>> basically.   This doesn't succeed often on the way to 5TB.
>> D) the biggest block size can be used but Multi-Part must be turned 
>> off and a second DLE and later gets to be very very very slow to add on
>>
>> Option D has NO limits to backups, but it is what needs the O(log N) 
>> check for single-stored blocks.
>>
>> This currently does a O(N) check against earlier blocks to check the 
>> cloud storage total after file #1 every time.   Verrry slow at only 
>> 1000 per xaction.
> 
> @Chris, thanks for these infos.
> 
> Sounds a bit complicated, I have to see how I can start there.
> 
> I won't have very large DLEs anyway, that might help.
> 
> I have ~700GB per tape right now, that's not very much. Although 
> bandwidth (=backup time window) also will be an issue here.

I now at last received credentials to that gcs storage bucket, so I can 
start to try ...

Does it make sense to somehow follow 
https://wiki.zmanda.com/index.php/How_To:Backup_to_Amazon_S3 ?

I don't find anything mentioning Google Cloud in the Wiki.