How important/useful is dual-bay (RAID1 mirror) in a home NAS, with cloud backup?

[pscont]

So here is a question

I have loads of photo's on a hard drive

which I have backed up to another hard drive and also burned a copy onto CD (which is a bit old school)

but ultimately - those backups will start to fail

and so at some point your data will, despite your best efforts; be lost.

What options do we have to stop them being lost forever?

Cloud.

[Hobosapien]

To protect personal data such as photos try to distribute the backups across various media that can be easily replaced periodically to keep it fresh from natural deterioration.

Also ensure at least one method is not sensitive to magnetism in case of EMP or solar storm.

So have copies across hard drives and solid state (SSD or flash memory sticks), on burned media (CD/DVD) and maybe even print out all those zeroes and ones if you're pessimistic about current tech resilience.

I noticed recently some DVD burners offer 'M-Disc' compatibility which aims to preserve discs for a thousand years. I guess by then the format will be as alien as coming across a Voyager disc in deep space.

Personally I let inevitable advances in tech take care of backup refreshes by way of moving to newer larger hard drives (next stop likely terabyte SSDs to replace my mechanical HDDs) or other sources so nothing is left to rot for more than a few years in one place.

[original PM]

Cloud.

And in the post apocalyptic waste ground which earth will become what do you think your download speeds will be?

[pscont]

And in the post apocalyptic waste ground which earth will become what do you think your download speeds will be?

who cares?

And remember children: the only successful backup is the restored back up.

[sal]

Go for the 1 bay model, then hook a cheap USB HDD and use the build-in Synology backup.

Source please.

You seem to be saying that the whole idea of RAID 5 is wrong.

RAID 5 is obsolete in Enterprise environments, still viable for SOHO as long as you are aware of the risks.

It's largely to do with massive increase ins size of individual disks and general decline in quality of individual drives mainly attributed to wide spread of cheap SATA disks in Enterprise environments.

The problem stems from the fact that while RAID 5 is rebuilding you are vulnerable to complete data loss. The process of rebuilding is very intensive and while it was fine 5-10 years ago with sub-TB drives nowadays with large 4TB+ drives can take more than 24h. I have seen it fail during rebuild once and another time it was extremely close - hours after the rebuilt a second drive of the same array failed. Not something you want to see in Production system.

The answer is usually RAID6, the added cost of 1 extra disk for parity is negligible especially in 10-12 disk arrays

RAID 10/1+0 etc. is usually for performance or 2 disk redundancy in 4 disk arrays, where RAID6 is pointless. At scale it becomes way to expensive.

[d000hg]

I do remember talking to a rep about this at a trade event quite a few years ago. I expressed amazement you could need better than RAID 5 (I think it was) but they pointed out the number of disks floating around in a data-centre, something with a very low statistical probability becomes pretty much a certainty at that scale.

[NotAllThere]

No, I'm saying RAID5 is a BCP option, allowing you to continue working following a physical failure at a reduced capacity. It is not a DR-preventing one. RAID5 volumes in a RAID0,1 configuration is the only disaster tolerant solution.

RAID 5 is VERY out of vogue nowadays - it's not particularly well regarded any more when better options such as 1+0 and 6 exist. A lot of people have found to their detrement that the R5 rebuild process is pretty harsh on the other disks and if a second fails before the rebuild you're up the creek.

Saw it loads back in my 2nd line days at an MSP - standard server load out was R5, so we'd toddle out, replace a disk and set off the rebuild which could take hours and hours. It wasn't unusual to then receive the "servers gone" call the next day

Fair enough. And I checked by configuration when I got back, and it is RAID 6.

[amanwhoisquiet]

How DO people here handle backup?

I have a old, unsupported 2 bay enclosure in the garage that i use to back up photos, music and other guff. The disks are raid 1. I also have a big USB disk plugged into that and it does a scheduled backup from the enclosure.

Other than that I depend on google. I pay £1.50 a month for 100GB of extra storage on drive or whatvever they've rebranded it as. Also use an awfully buggy client on desktop machines that copies selected local folders up to google - and drops photos into the unlimited photo store you get with google (albeit compressed a bit). This doesn't do recovery though really.

I can recover music and other stuff, but photos are the big one I'd be upset about.. and current work I'm in the middle of. I once dropped a portable harddisk with a lot of photos on a tiled floor and over half of them were lost. I'm not letting that happen again - buy a case for those big usb hdds!

[d000hg]

Photos are an interesting one. They're typically files you don't actually need to access or have locally, you just want to be damn sure they are backed up. If you lose your local copy it's unlikely to matter that it takes some time to get them back. Individual photos and most documents are so small that in fact, accessing them from Cloud on-demand as needed is barely a problem for productivity.

[Hobosapien]

When I scanned my parents old photos of the family I gave various satellite family members a copy by way of a crimbo pressie of a digital photo frame using a flash card of the photos. Others I gave a playable DVD version.

Distributed backup and crimbo pressies sorted at the same time.