Advice on My Back up Idea

[AndyM]

I have been pondering how my NAS is set up and how to best protect my files all given I am not, and have no desire to be, a Unix expert. The original AS6604T set up defaulted to a raid 1 - the protection of redundancy seemed like a good idea at the time, so I have left it. I back up to an old USB drive and that works but the day is not too far off it will be full and then what. Obvious option is to buy another USB drive but my back up process kind of works against this idea. I have the drive attached to an old PC and that receives the file updates via the LAN, then to the USB drive. So I am considering this option;

Buy an AS1104T and set it up as JBOD. After getting the files copied over reinitialize the AS6604T to JBOD as well - keep the two in sync using the Backup & Restore utility or Syncthing. The advantages I see:

1) Simple - drive one on both Nas's would be the same; ditto drive 2 etc. - would have a back up in a different location.
2) Maximize the drive space available - no mirror but no duplication (but with a back up).
3) Presumably there would be no compatibility issues with the two Nas's: same operating system, apps etc.
4) Recovery should be as simple as copying the drive - no fussing with coding.

The disadvantage is the cost of the second NAS - I can live with that. I gather such an arrangement would not be as fast as a raid array, but, as I am the only user, I don't foresee that being a problem.

My data consists mainly of fairly large, non-critical MP4 files that don't change. New ones are added daily. I am assuming KODI (love it!) would work on either.

I welcome comments.

Andy

[Nazar78]

I hope you've done extensive research on jbod as backup and carefully weight its pros and cons, IMHO heavier on the latter. Jbod should be used as nothing more than a temporary or scratch space.

Similar to raid0, besides no redundancy for disk failure, you will not be able to increase the size of the disks in the future other than adding new disks but limited by the number of available bays. So further down the road if you decided to upgrade the disk size you'll need to reinitialize the span. Additionally 100% recovery is difficult to certain extent almost impossible.

A scenario... Ok cool you have another jbod secondary backup, a disk failed on your primary or you decided to increase its disks size and after you replace then reinitialize, you attempt to copy over. Depending on the size and transfer method, best case 1tb single file est 1hr over 2.5g to transfer with 94% efficiency. What are the chances if your secondary jbod had one of its disks failed too during the restoration process? Do we foresee the need of a 3rd jbod backup?

You're better off using separate disks for backups if you choose simplicity but at the end of the day it's your call. I would advise at least a 2x raid5, you don't actually need another NAS just an enclosure but again minus the technical knowledge to set this up then maintain it, just get another NAS as you've planned initially but just avoid jbod if possible.

[AndyM]

Hi Nazar,

Much appreciate the comments - always willing to learn.

I take it you wouldn't like raid 0 any better than jbod? I got a little concerned about adding a disk to a raid after reading some of the problems even experienced users are having.

Interesting point on the transfer efficiency of 94%. Does that mean the odds of the second drive failing is 6%? or that there is typically a 6% error rate on file transfer integrity? Either way it argues to stay with a raid for redundancy - I wouldn't like to lose 6% of my files.

I looked at the simple non-nas enclosures as a choice but got concerned about the cmr vs smr thing (my enclosure is really slow), how well they connect wirelessly and the longevity of the drives - I read stories about lots of failures, though I have had several that lasted quite well.

I guess drives are NAS specific? Even if I had both in a Raid 0 set up there would be no ability to interchange drives even if both are using the same operating system?

Again, thanks for the input.
Andy

[Nazar78]

Hi Andy,

No problem.

I take it you wouldn't like raid 0 any better than jbod?

No, I love raid0 but I wouldn't use it for backups. Yes for OS, but data mounted to other raid levels. Sames goes to jbod, not for OS though but a large temp space for data dump.

I got a little concerned about adding a disk to a raid after reading some of the problems even experienced users are having.

Nothing to be concerned with, as long you have backups with good strategies like the 3-2-1 rule. Many NAS users with raid out there, we can only see a few posting issues.

Interesting point on the transfer efficiency of 94%. Does that mean the odds of the second drive failing is 6%? or that there is typically a 6% error rate on file transfer integrity? Either way it argues to stay with a raid for redundancy - I wouldn't like to lose 6% of my files.

I'm referring to the transfer rate efficiency. I.e. 1Gbps file transfer over LAN, typical overhead/traffic which contributes to the 94% efficiency, 1000Mbps / 8bit * 94% = 117.5MB/s, this is roughly the usual speed you'll get over 1Gbps, * 2.5 for 2.5Gbps interface. Hdds are unpredictable, it can bust anytime, high or frequent temperature changes often contributed to this. The previously transfer rate calculation times your size of data equals how long you need to stress the hdds. This is subjective of course, my NAS drives shot up 75 degree celsius long ago 15 deg way above manufacturer's spec due to ventilation issues but still working ok till today. What I'm trying to say here is that, if you're lucky nothing happens during the restore transfer then it's good. But what if one of the disks in the secondary jbod fails during restore? The restoration process will halt, recovery will be tedious and not 100% guaranteed. If these was raid 1/5/6/10, you can simply hot-swap the said disk, rebuilt it online while still continue your restoration process.

I looked at the simple non-nas enclosures as a choice but got concerned about the cmr vs smr thing (my enclosure is really slow), how well they connect wirelessly and the longevity of the drives - I read stories about lots of failures, though I have had several that lasted quite well.

"cmr vs smr" is the drive technology, nothing related with NAS or enclosure but don't use smr drives with raid. With a USB3 enclosure, you should get around 300MB/s for ssds and 200MB/s for modern hdds. I even have one of the ADM OS raid 1 mirror in the USB enclosure on SSD. Edited: Not official but the idea is that all my 8 hdds (x4 in NAS and x4 in enclosure) can sleep well while most system reading is done from the single external ssd. I also moved the apps like ubuntu desktop, docker, website stuffs to this external ssd, the tmp and logs to ram, turned off access timestamp, turned off swap. All these helps to cool down the area while the 8 hdds are asleep. With 8x hdds you can imagine the amount of heat they generate. Does it work? I ran some disk read benchmark on the OS array, all reading goes to the external ssd none of the hdds woke up. You can do wonders on the NAS with a little tweaking.

I guess drives are NAS specific? Even if I had both in a Raid 0 set up there would be no ability to interchange drives even if both are using the same operating system?

In a software raid, you can always move the raid0/1/5/6/10 to another linux box running mdadm.

[AndyM]

Thanks for all the great info Nazar

I should qualify to be on Asus's Christmas card list this year. I bought an 1104 yesterday to go with my Asus PC, Router and 6604. I somehow like the NAS idea as opposed to adding more USB drives but it may have an impact how I have to approach this back up procedure.

At his point I have 2 drives in the 6604 set up as raid 1 and plan to add 1 disk and move to a raid 5 when I need to add more space. I was thinking to put a single drive in the 1104 as a raid 0 for now and move it to a raid 5 when I need to expand the 6604. It would have been cheaper and simpler to just add the usb drive but I like the fact the 1104 can grow as needed. This of course assumes I can migrate form a raid 0 to a raid 5 in the future. Sounds like that is not ideal as you recommend against a raid 0 for back up but could it work as an interim solution?

I am not familiar with the 3-2-1 rule; will need to find out about that.

Great info on the transfer rate efficiency - I have always wondered what rates were to be expected. About the best I get transferring files wirelessly to the NAS is @ 60 MBs. I assume the 117.5 is a wired rate - if not I have another mystery as all my gear is fairly new. I have never seen anything near 200 MBs. My pc uses an ssd and the NAS has 2 10TB seagates (cmr) about a year old so I am not sure how I would get those kind of numbers. I did an ssd to ssd transfer (a mirror of my PC ssd) and got great rates - about 600 gb in 14 mins whatever that works out to.

Good to hear about the drives temps - I found the drive noise annoying so I built an enclosure and have been monitoring the temps - I am currently running in the high 40s typically which I gather is within spec. I have bought some more small fans that may get that down a little more once I get them installed. Love the idea of using an ssd to keep the HDDs quiet - more info on that would be great to hear. Moving apps to an external ssd and making it all work is well beyond my abilities at his point but maybe some day... I will be a little more wiling to experiment on the 1104 to learn.

Cheers
Andy

[Nazar78]

No problem. If you can get your hands on an extra NAS and hdds why not? Go for it. For myself I would go for a 4U 24 bay but where I live is quite hot 33deg c at night and the electric bills are also high so I'm quite conservative for long runs. I even lowered my RTX3080 GPU power to 50% lol. Perhaps when my space gets limited, I'll get another 5 bay enclosure plus some 16tbs for the old nas, shift the old 10tbs to the new 5 bay. Probably then also the need to upgrade my secondary enclosure disks too, not forgetting a new UPS to handle x1 4 bay NAS and x2 5 bay enclosure. Please also don't forget about UPS when you're running mechanical disks.

Bottom line is, see my foreseeable upgrade plan above? I don't use any raid0 nor jbod so the upgrade can be done easily by hot-swapping the disks online, shutdown then shift the disks to another device.

[AndyM]

Just an update and a thank you to Nazar for all his advice.

Took a while but I now have the 1104 set up as a raid 1 backup rsync'd to the 6604. I even got a 2.5 g switch installed in the mix and it seems to work pretty well. I still have some tuning to figure out (still stuck at the router speed level - I think I need to learn how to get LAN 2 to feed the switch vs going through the router) but all in all I pretty pleased a rookie, non-tech got this far (with some good advice of course). Much better set up than the old external drive approach.

Cheers