Is that true Kili? - I've had various servers and NAS's with only two drives running Raid 1.
From recollection both the NASs (2 drive bays) came configured with Raid 1. Don't the higher Raid levels require more drives (more than 2)?
Yes you need at least 3 drives for a raid 5 array, but more is better and I would use another for a hot swap spare if I had a NAS. If two drives fail at the same time in a RAID 5 array the data is lost hence a hot swap spare would automatically kick in should a single drive start to fail .
We used to configure our servers with the boot/Operating system drive as RAID 1 and the data drives as RAID 5. RAID 6 can lose two drives in an array and still function so that's likely what's used these days or RAID 10 may also be used by most large enterprises these days as I understand its much faster and more reliable then RAID 5.
If your NAS is configured for RAID 1 and as long as both drives don't fail at the same time ( unlikely, but I have seen it happen infrequently in RAID 1 arrays on some servers I used to manage) that should be fine if all you need is a copy of your main drive . That said most drives are now SSD drives so no mechanical arm or read write spindle and therefore more reliable and longer lasting.
'The power of accurate observation .... is commonly called cynicism by those that have not got it.
I think it comes down to the typical cost/benefit/risk ratio. I bought my first NAS (2 bay, Raid 1) in 2010 and so far that has had one drive fail. Maybe lucky - but in ALL the time I've had laptops/PCs/servers/NASs, that is the only drive that has failed on me.
When the drive failed in the NAS, I replaced the drive and also bought a 2nd NAS (as I thought, at that time, a nearly 10 year old NAS had paid for itself) - again a 2 bay, Raid 1 setup - so now my main NAS is 'new' -
and I backup from laptop to new NAS and new NAS to old NAS.
The additional cost to allow for multiple drives failing at the same time, to me, seems unnecessary - as isn't it also counter productive? The more drives, the more chance one will go wrong. Maybe the way to go is to make sure the drives put in the NAS are good quality? Backblaze publish AFR stats for different drives. - it also looks like SSD drives (that look like being the future anyway) are a good bet.
If I was running a setup with multiple servers supporting millions of connections with a critical uptime requirement, then I'd probably think differently! Maybe when I get two drives crash at the same time (but if two fail at the same time, why not three...four...?) I'll definitely think differently!
I wouldn't recommend having a single bay NAS though!
We have a variety of external hard drives and USB sticks as backup but we don't try to back up everything in the same place, so for example I have 2 backups of the files on my laptop on USB sticks and a third stick with the windows recovery "disk", plus some hard drives (some reused from computers that we've put bigger disks in or thrown away because of other things failing) with music, photos, old work stuff that I might want sometime and so on. Relatively inexpensive that way but needs a bit more organisation than backing everything up onto a NAS in one go. There are some pretty big USB sticks at sensible prices these days.
Doncaster, South Yorkshire. Soil type: sandy, well-drained
It's horses for courses isn't it? I only went NAS for two reasons - 1) I had old vinyl that I wanted to digitise (and as it turned out, old video - and masses of digital and digitised photos) and that I wanted to hear/see through multiple devices (IE I can listen to my music in my bedroom, kitchen, bathroom... view my photos on the TV, laptop, phone....anywhere I have a DLNA connectable device) 2) I wanted to backup my 'stuff' - and at that time I had loads of work 'stuff' and my son had all his uni work. For me a NAS was ideal - a bit like a super large USB stick, and connected via the network.
My OH has network drives (don't know if they're NAS or just single drives) that he uses for that sort of stuff and I can access all his music, videos, ebooks and suchlike and watch/listen on the TV or my laptop or tablet or phone, but I back up my own files as well, including my photos and music (mostly ripped from CDs to put on a USB stick that I have in the car, this one didn't come with a CD player - that's old hat now!!). I just wanted to show that it doesn't have to be expensive. We've probably got way more copies of some things than we'll ever need
Doncaster, South Yorkshire. Soil type: sandy, well-drained
Same here for the car... I didn't even have a USB port on the radio, so I use an MP3 transmitter. I then knocked up my own software to randomise my music and put it on a USB that then plays through the transmitter to the car radio. Convoluted.
It's not just cost - it's space as well though - just checked - and the NAS currently has:
(Linux)E6540-64 :stevet : /mnt/212/media> du -h . --max-depth=1 241G ./Music
54G ./Pictures
597G ./Videos
So that's about 900Gb. I do store my music in two formats though (that's a legacy) - as I tend to play 'FLAC' (a lossless format) indoors but my car (and the MP3 transmitter) needs mp3 (a lossy format).
I've just ordered a 1Tb USB flash drive for £9.99. Of course it may turn out to be rubbish and it's only USB 3.0 not USB C, but at that price it's worth a try.
Doncaster, South Yorkshire. Soil type: sandy, well-drained
@JennyJ Be careful before you commit anything important to it. A colleague bought a similar one, and although he appeared to successfully copy over 500GB of data to it, we found it was actually a 16GB stick which had fake internal firmware which simply kept overwriting that 16GB. Google 'fake usb drives' for more info. and ways to test. You may be lucky though.
A trowel in the hand is worth a thousand lost under a bush.
@BobTheGardener , nothing is ever my only copy or even only backup of anything. If it's duff it'll get a poor review and returned for a refund (after properly clearing any data). It's from Amazon and I've found them pretty good at returns and refunds for things that turn out to be "not as described". I'll let you know how it goes and you can tell me "told you so" if it turns out to be a fake
Doncaster, South Yorkshire. Soil type: sandy, well-drained
Posts
Yes you need at least 3 drives for a raid 5 array, but more is better and I would use another for a hot swap spare if I had a NAS. If two drives fail at the same time in a RAID 5 array the data is lost hence a hot swap spare would automatically kick in should a single drive start to fail .
We used to configure our servers with the boot/Operating system drive as RAID 1 and the data drives as RAID 5. RAID 6 can lose two drives in an array and still function so that's likely what's used these days or RAID 10 may also be used by most large enterprises these days as I understand its much faster and more reliable then RAID 5.
If your NAS is configured for RAID 1 and as long as both drives don't fail at the same time ( unlikely, but I have seen it happen infrequently in RAID 1 arrays on some servers I used to manage) that should be fine if all you need is a copy of your main drive .
That said most drives are now SSD drives so no mechanical arm or read write spindle and therefore more reliable and longer lasting.
'The power of accurate observation .... is commonly called cynicism by those that have not got it.
George Bernard Shaw'
241G ./Music
54G ./Pictures
597G ./Videos
So that's about 900Gb. I do store my music in two formats though (that's a legacy) - as I tend to play 'FLAC' (a lossless format) indoors but my car (and the MP3 transmitter) needs mp3 (a lossy format).