How to organize a media server + file dump + torrent downloader + web and mail server?

Question

RAID

Good luck to everyone!) There has never been such a task, so I ask for advice in the direction of studying the materiel.
There is an old piece of iron on i3 with 4 gigs of RAM (if not enough, you can grow). There are a bunch of different screws that are planned to be hooked into the raid, it's not clear which one. Required:
1.1. On this piece of iron, start a media server that will distribute streaming video (DLNA) to TVs. Which server to choose and which axis to put, despite the fact that you immediately want to have a web server with a database?
1.2. On the same piece of hardware, you need to make a file storage (movies, music, documents, software.) At the same time, you need to do it so that you can pick them up from the external network if you wish. What is faster / safer than ftp smb or something else?
1.3. There should also be a torrent downloader, which is enough to give a torrent, and she herself has already unloaded it and distributed it further. What software to look for?
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2.1. I want to raise a web server for a narrow group of people. about 15-20 people, with a database ..
In a very distant vague prospect, at first there will probably be a small web project, which, with an increase in flow, will move to another place. Again, what axis is it to twist?
2.2.Now the mail is attached to Yandex and I understand with my head that it would be better to leave it there, there is less trouble, but still there is a desire to transfer it to your server.
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3. With regards to RAID, what should I do if I need to regularly backup part of the information (documents, personal work, personal photos / videos, server, mail), and the second part is movies / programs downloaded from the Internet, etc, that do not carry any value.
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4. In the order of delirium. To speed up the work, will it be possible to shove the OS into the RAM?
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5. Is it possible to run virtualization on this machine?
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6. I understand that what looks on the web a priori has risks of hacking, but still, what is the probability that, with all that you want to implement, personal data will go to the side?

Answer 1

1.1 - no advice - no experience
1.2 - on samba locale, from the outside through a browser - owncloud for example, security - long passwords and ssl
1.3 - transmission with a web muzzle
2.1 for owncloud you will need php add mysql and apache / nginx to taste understand better.
2.2 options sea, look at a bunch of exim dovecot spamassasin clamav mysl and admin panel webmords -postfixadmin, for users to look at boxes roundcube/horde
3. here you need to proceed from the number and volume of disks.
4. Linux does not need it.
5. you can, but it will add trouble - the benefit from this is not obvious.
6. From the experience of working in a hosting provider - 98% of cases of data theft, hacked accounts, etc., are due to the human factor - dictionary passwords like "qwerty123" passwords in txt files or saved in a browser, stolen emails due to banal secret questions ... .the list is endless. and only 2% are problems in the software.

Answer 2

ubuntu 14.04 or centos 7, you can raise kvm virtualization on them, or it’s better not to collect docker containers using
raids at all, backup important things to your computer or somewhere to the thread on the Internet and let everything be on separate disks

Answer 3

Try freeNAS server, it can do everything you need (except virtualization, perhaps), based on freebsd. In general, it is better to take a server OS from what is closer to you and raise everything your heart desires on it. I am for CentOS or Ubuntu.

Answer 4

there are ready-made nas operating systems from synology or freenas, open media vault.
all Linux, everything is customizable.

Answer 5

Openmediavault on Debian 7. It's convenient that a lot of things are configured out of the box and are configured via the web interface + monitoring with sending by mail. What you need outside the shell is installed through the Debian package manager. Note that configs can be overwritten by the shell.

Answer 6

4. system \ base on ssd + ups, buy more if not