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krutsch · 06-06-2015, 17:24

(05-06-2015 11:57)simoncn Wrote:
(04-06-2015 23:53)DavidHB Wrote: That's not exactly the way it works. There are different sorts of RAID arrays, but the concept of true RAID is that, if a disk fails, the rest of the multi-disk system contains the wherewithal to reconstruct the contents of the failed disk on the replacement. In effect, the array repairs itself. This reconstruction is of the whole data structure, rather than of individual files, and it tends to take a long time, which is a significant disadvantage. For a fuller and more technical description, see this Wikipedia article.

This is true for a drive hardware failure but cannot protect against any other causes of file corruption such as software problems or human error.

RAID arrays tend to operate at the block level, as opposed to the entire disc. They "scrub" in the background to detect questionable blocks, sectors and/or tracks and will reallocate those elements and rebuild from the remaining data + parity. There is also the drive's internals SMART data which can provide hints to the RAID system, but in my experience in the storage industry, once a SMART trigger occurs, the whole drive is near death anyway. I use a Drobo RAID device for primary storage, because of its scrubbing function that will detect bit-rot, as well as provide maximum warning for failing drives.

What Simon states is most important: the vast majority of data loss comes from human and software errors - by an order of magnitude. So, any backup strategy must protect you from human errors that go undetected for a relatively long period of time.

Buy three, cheap external drives and rotate your backups between the three of them, always keeping one drive with a relatively old copy in a safe place. Considering the time, money and effort that goes into your music collection, and how cheap 1TB drives are, this is money well spent.

See this link for a backup rotation scheme that works well; it's written from the perspective of tapes, but works for external disks, as well.

http://en.wikipedia.org/wiki/Backup_rota...father-son

Loop4fun · (This post was last modified: 06-06-2015 23:47 by Loop4fun.)

Speaking of human error, I really screwed up my database a couple of weeks ago by accidentally moving rather than copying files from my Synology NAS to an external USB drive (Lumin L1) for backup. I caught it about 2/3 of the way through, but it was too late, and I ended up with a mess of two or three music folders of everything. I just didn't know where to start, as getting rid of all the duplicates was a huge job.

Thankfully, I had installed Amazon Glacier and had backed all my files to their server. It is very inexpensive to store, but costly to restore. It's not a program for frequent retrieval.

Anyway, I moved all the files off the NAS and restored everything from the prior week's backup from Glacier. It took about 4 days and cost about $300, but worked 100% as advertised. The Glacier package is available on Synology, easy to install, and the $300 was money well spent. I never thought I would have a need to restore from this site.

gnomus · 07-06-2015, 06:57

How to Reformat Old Synology Drive?

Does anyone have any ideas how to reformat the old 3TB drive that I have taken out of my DS213J? As mentioned above, I have gone down to having a single disk in the 213. I put the disk that I removed into the USB docking station that I have attached to the 213. However, it does not appear either within the DSM 'File Station' or Windows Explorer. As such, I cannot reformat it.

Is there something obvious I am missing?

gnomus · 07-06-2015, 16:30

(04-06-2015 11:06)simoncn Wrote:
(04-06-2015 06:55)gnomus Wrote: I don't know how to account for these - and I have many of them (thousands). I do recall that at one stage, before someone here (Simon) showed me the light, I was ripping CDs directly to the Synology, and then copying from there to my back up locations (such as the QNAP). I don't know if that might be the cause. I also don't know if I should work my way through my QNAP library deleting all of these @ea directories and their contents. Some of them are several megabytes in size

Does anyone have any thoughts?

I believe these are thumbnail images that are created automatically by something in Synology DSM. You don't see these folders on the Synology because Synology DSM treats them as hidden folders. MinimServer doesn't use these images and there is no problem with deleting them.

I would counsel against: doing a Windows Explorer search on "@ea"; select all; then delete all. When I tried this on my QNAP, Windows not only selected all my 'Eartha Kitt' albums, but also any single file with 'ea' in the title.

Very nearly a complete disaster. I think I might leave things as they are.

simoncn · 07-06-2015, 18:31

(07-06-2015 06:57)gnomus Wrote: How to Reformat Old Synology Drive?

Does anyone have any ideas how to reformat the old 3TB drive that I have taken out of my DS213J? As mentioned above, I have gone down to having a single disk in the 213. I put the disk that I removed into the USB docking station that I have attached to the 213. However, it does not appear either within the DSM 'File Station' or Windows Explorer. As such, I cannot reformat it.

Is there something obvious I am missing?

You should be able to reformat the disk using Control Panel > External Devices in Synology DSM.

gnomus · 08-06-2015, 06:21

That is exactly what I had to do. Thanks again SImon.