Do i need a CD player, or can I use Mc Book?

sfar has spoken some very wise words.

After several reloads of my entire library I decided to to upgrade to a NAS drive thar supports dual drives in a mirrored RAID configuration.

This approach guarantees that both drives carry a copy of my library and in the event of a drive failure, I simply replace the faulty drive and the NAS drive takes care of copying data to the new drive automatically. No backups are required.

When I first built the NAS DRIVE i used a couple of spare drives from old computers. they worked very well, but I later found out that RAID really requires server quality drives.

You guessed it - one of the drives failed.

I simply popped in a new server quality drive and the system took care of everything else. I then replaced the other old drive with a second server quality drive.

The system has been running flawlessly.

I've downloaded tracks up to sample rates of 24/192 and never encountered any problem with this configuration. 

I stream via my iMac that is connected to my DAC via USB. Both the iMac and NAS drive run over an ethernet wired connection (not wireless) to maximize transfer rates.

I use iTunes for library management and Audirvana to trnafer data to the DAC

Hope that helps :

Unfortunately RAID does not protect from controller failure, virus, lightning or simply operator's mistake.  That's why I keep 2 backup copies instead.  Second copy is an additional protection from something bad happening during backup.  Also RAID does not protect from fire, theft etc. while my second backup kept at work does.  In addition, unpowered drives tend not to fail.  RAID might be a good solution, but I would still make one extra copy.  Drives are cheap these days.

Once network (Ethernet, WiFi, Async USB) is used payback program does not make any difference (unless it is making additional processing - like oversampling).  It is because data and not the music is sent (no timing) while timing is recreated on the other side of the network bridge.  At this point nothing on computer side makes any difference (program, speed, amount of RAM etc) - saves a lot of money.  You can also use computer during playback (as I do) - it won't make any difference.

kijanki's solution of having two backup drives is very smart and exactly what I did before I retired. I rotated a weekly backup of my complete primary drive to two drives using SuperDuper so that they would be bootable from my laptop if my iMac failed and I kept one of the backups in my office. 

Since I've retired I don't have a good off-site location but I keep the second backup in a fire and waterproof case locked inside a locked metal gun safe in my garage.

All this may sound like overkill but in the years I was responsible for technology at a large newspaper I did so much grief counseling with people who'd lost months of work because they never made a backup that it made a big impression on me. Once you get into the routine of backups and maintenance of your computer it doesn't take much time or effort and it will help you get a good night's sleep.

To your question about whether to focus on high res downloads, the reality is that most recorded music is not available in high res formats and likely never will be. Focus on the music you love, not on its resolution. Great music at 128 kbps is still great music.

Unfortunately RAID does not protect from controller failure, virus, lightning or simply operator's mistake.  That's why I keep 2 backup copies instead.  Second copy is an additional protection from something bad happening during backup.  Also RAID does not protect from fire, theft etc. while my second backup kept at work does.  In addition, unpowered drives tend not to fail.  RAID might be a good solution, but I would still make one extra copy.  Drives are cheap these days.

+1.  A couple of additional things that RAID doesn't protect against:

-- If the RAID array's power supply were to fail in such a manner that it goes into an overvoltage state, all of the drives in the array could be simultaneously destroyed.  A well designed power supply will include protection mechanisms which minimize that possibility, but I wouldn't assume that all power supplies are well designed, especially in low cost consumer-oriented products.

-- Undiscovered bugs in the RAID controller's programming.  User comments that can be seen at Newegg.com about certain RAID devices include significant numbers of instances in which data was lost due to this.

Also, if the array's controller circuitry were to simply fail without harming the hard drives, but the same or a similar controller is no longer available, depending on the RAID mode that was used the data on the drives may be unrecoverable.

Regards,
-- Al