1. 50GB for lossless music,
2. 20GB for lossy (e.g., 320Kbit/s MP3, AAC, WMA, etc.) music
3. >=100GB (and growing) for photos
4. >=1TB (and growing) for HD TV and movies
Wish this helps.
I have 2x1 TB hard drives plus 1 240 GB SSD in use right now - first 1 TB HDD flows over, the second is about half way full.
I store all my CD's as a FLAC rip, plus plenty of mp3s (nothing under 256kbps), about 250 GB on the first HDD is kept occupied by my music libary, the rest of it being videos
I keep plenty of iso images of my old game CDs/DVDs, for convinience, a pretty big Steam collection and some virtualbox images on my second hard drive.
Both HDDs are cheapo WD/hitachi stuff for about 80 Euros each. The SDD is a Crucial M500 240GB I bought on amazon for about 90 Euros (was on sale, pretty sweet).
I have a NAS with 2 mirrored 2 TB - of which >1TB is full of Music (FLACs and HighRes) plus 2 separate 2 TB disks with Music as a backup.
PLUS - about 350 GB of Music on my laptop (FLAC and MP3s) and 160 GB on my old Ipod and 160 GB on my AK100
you should, when an ssd goes it happens utterly without warning.
one day all is well, next day you turn on and drive is totally dead and completely unrecoverable. drive cant even be seen in the bios.
I upgraded an old macbook (first unibody design) with an SSD. To be fair, Apple didn't officially support this but neither did they caution it wouldn't work. Installed it and all was well, blazing speed, together with the 8 Gb I had installed it was like owning a brand new laptop. After one month: kaboom. No warning, no nothing and as was said above, not even detectable. Luckily I had backups on a conventional system and offsite. I replaced it, same thing happened a couple of weeks later. When they fail, they fail hard and without warning (at least in my case). Once more: having at least one full backup available is absolutely essential with any system.
I have about 400GB of FLAC, excluding 300 classical CD's which are yet to be ripped. I use an external 3TB USB3 (3.5 inch) hard drive for permanent storage and playback. I rip to (and use for short term storage) an internal RAID 10 array (4 x 3TB) and also copy all FLAC and video to an external RAID 5 array (5 x 3TB) used purely for backup. I also copy all FLAC to a portable (2.5 inch) 2TB external hard drive. I also have 128GB in my iBasso DX50.
Slightly OT, but a salutary lesson. As mentioned above I was running RAID 10 (4 x 3TB). RAID 10 both distributes the data over two drives (for speed) and duplicates each drive (for redundancy). I also was backing up to an external 3TB disk. About the time of the original post I started noticing errors on the backup drive. So I decided to copy all of my backup data to the RAID 10 array and swap out the faulty backup disk. So I copied the backup data back to my RAID 10 array and ran test software on backup drive to confirm that it was in fact faulty, which it was. The disk diagnostics destroyed the backup data - but no problem - it was on the RAID 10 array.
At this point my RAID 10 array lost two disks - irrecoverable read errors. They catastrophically fail all self-tests and read diagnostics. No recoverable data.
I've lost 12 years of company data and personal data (except my music which was backed up elsewhere). Completely and utterly unrecoverable.
The two RAID 10 disks that failed were purchased new and less than two years old (about 20 months of use). They were purchased at slightly different times so that all disks would not be from the same batch. My system is high end and runs incredibly cool, so disk heating is never an issue.
Sometimes when you think you've got everything covered you couldn't be more wrong.
I'm now purchasing high-end enterprise specification hard-drives. Be warned if you're running consumer spec'ed hard drives, they will fail at some time and as you can read here - some much sooner than later.
Please learn from my hubris.
It might also be noted that server HDDs will fail tests earlier then normal consumer hard drives, before they actually fail. Which gives you head room to get the data off of them before they die. When consumer drives say they fail, they are probably already dead.
It occurs to me that everyone could just pool their money and hire a bunch of eidetics to memorize their Beatles discographies and Gmail passwords.
If you're not keen on the average 68-year life expectancies there's always genetic modification; though I guess you'd have to pay extra for that. Otherwise they should be pretty foolproof.
Some Terabites, both for audio and video (plus some more terabites for original recordings). Samsung Pro SSD-drives for OS and software and many separate 'normal' HDDs for storage (not in RAID), nowadays avoiding Western Digital (WD) HDDs (lost important and irreplaceable original recordings and info in one WD HDD and also it's backup on another WD HDD!)