What External Data Storage System Do You Use?

Personally, I go for individual external HDDs connected by USB - multiple of these for larger systems, with the cameras split across them. It's an easy and inexpensive solution, and provides a certain amount of redundancy - if one drive fails it doesn't bring down the whole storage solution (unlike RAID-0), don't affect all cameras, and is easy to rectify by simply swapping out that one drive. Any USB 3.x protocol is easily fast enough to cope with a couple dozen cameras capturing continuously to each drive, or many more when capturing based on motion. Desktop Macs give you 4x USB-A ports, and it's easy to add more via Thunderbolt/USB-C hubs if necessary.

Many customers use RAID setups and they can work well, but they add complexity and therefore failure modes to the system. When customers ask us for help with drive issues that they have had trouble solving themselves, it often turns out they are using RAID setups, and it's then often difficult to pinpoint and fix the problem. One advantage of some specific RAID setups (e.g. RAID-5/6) is that they offer whole-storage redundancy, so that if a drive fails, you don't lose any data. However when this happens, and for a significant period after the failed drive has been replaced while the RAID is recovering, it tends to slow down the whole unit significantly, which can lead to problems capturing video during this period.

I would say that RAID units are typically the best solution when you really need huge amounts of storage, or whole-storage redundancy, otherwise individual drives are the way to go.

Thanks for reporting your experiences! Yes, HDDs can be relied upon to fail every now and then, and of course especially when there is an important event to record :) RAID 1 is a good solution to provide redundancy in case of a single-drive failure. To answer your specific questions:

1. I have read the claims by the manufacturers, but have seen no real-world test data comparing surveillance drives with standard drives, so at this point I'm basically agnostic on this. It's plausible that designing drives with certain characteristics will make them better for video surveillance, though the lack of test data means that we basically have to rely on manufacturers' marketing claims.
2. Do you mean multiple volumes in a RAID? I've always gone for the advice to use identical drives, though this of course is not strictly necessary. High-spec drives aren't too much more expensive than low-spec ones, so it's worth spending the bit extra.
3. Personally, I wouldn't replace drives too frequently, if they are working well. Once you have a drive that has been working well for 3 years, it's quite likely that it will continue to to work for a few more. Replacing it just means that you're replacing a known good drive for an unknown one. Perhaps after 5 years or so this makes sense, as the probability of failure then starts to increase significantly.

The cloud storage company Backblaze recently published a blog post called Hard Drive Life Expectancy, which has some useful information related to the above discussion. Key takeaways are:

• Failure rates between different brands/models of HDD drives vary considerably.
• For some drives, failure rates increase significantly after year 4; for others, failure rates are fairly linear all the way up to year 6.
• While it used to be the case that first-year failure rates were higher than year 2/3 failure rates, this does not seem to be the case with modern drives (perhaps due to better manufacturer quality control to weed out any drives with obvious defects that would cause early failure).
• It should be noted that these results don't come from a random sampling of drives; Backblaze chooses their drives very carefully, so it's a bit difficult to know how these results generalise.

So I think the takeaway from this is to:

• Try to choose known high-quality drives with good ratings/reliability data to start with (don't skimp) - see if you can find failure data published by Backblaze or others
• For critical applications, replace the drives every 4 years even if they show no signs of failure
• For less critical applications, replace the drives every 6 years or so

(BTW Backblaze is a great cloud/backup service - we use their automatic backup solution ourselves!)

The NAS credentials are stored by the system/Finder when you first mount the NAS on your Desktop (provided you tick this box). They aren't stored by SecuritySpy - when you set the NAS as a capture destination in SecuritySpy, it saves a bookmark to that location on the file system, and subsequently when SecuritySpy attempts to access that location, the system springs into action and mounts the NAS with the saved authentication that it has stored.

Hi @jlbrown this is unusual and shouldn't be due to closing the files (though I suppose its possible). Do you have any other task related to the disk that is scheduled for midnight (e.g. a backup or any other activity that reads/writes from this disk)?

Hi Mech33. My Synology was fairly full. I followed these instructions from Bensoft Support:

- Quit (or force-quit) SecuritySpy.

- Unmount all NAS instances on your Desktop (drag them to the Trash).

- Disconnect both Ethernet cables from your Mac, so that it is not connected to any network.

- Open SecuritySpy; it should now open without hanging.

- Select the menu option at SecuritySpy > Debug > Clear All Camera-Specific Capture Destinations.

- Select the menu option at SecuritySpy > Debug > Clear Old Backup Files.

- Go to Preferences > Storage, and click the "Reset" button.

- Reconnect both Ethernet cables, and mount the NAS in the Finder.

- In SecuritySpy, under Preferences > Store, click the "Set" button and select the NAS.

- Quit and reopen SecuritySpy.

Only difference was that I told it to use the internal SSD rather than the NAS going forward. All works fine now.

But I will reconsider recording to the Synology NAS in the future - just glad got everything working. Thanks again to Ben for the excellent software and support.

James.