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Backup: Keeping superceeded versions?
I currently have an Ultra-6 as my main storage device and it is being backed up to a DriveBender box using something called SecondCopy - which keeps up to 20 versions of any given file. I think I...
This has helped some users: https://community.netgear.com/t5/ReadyNAS-in-Business/ReadyNAS-312-Need-Help-Understanding-Snapshots/m-p/936586/highlight/true#M3041
Each snapshot holds the entire share at the time the snapshot was taken - all the files are visible. The reason it is space-efficient is because the data blocks that haven't changed are referenced by both the main share and the snapshots. So unchanged files are only stored once, files that changed once are only stored twice, etc. But they appear in the share and all the snapshots.
There are some shares where snapshots can create problems. Two common examples are shares holding SQL databases that are frequently updated and shares for downloading torrents. The frequent changes result in a lot of snapshot space being used, and also a lot of file fragmentation. Just something to keep in mind.
Note that if you are using Windows 7, 8, or 10, there is a right-click function that shows previous versions of a file. If you are using snapshots, you can right-click on any file in the share (or any folder) and see the previous versions for that file. That simplifies your use-case considerably. (There is a way to turn that feature off if you use custom snapshots).
>No need to guess which snapshot had the old version in it.
I'm starting to feel like I'm turning into a tarbaby on you over this.
Can somebody point me to some docs that explain snapshots so I can dope this out on my own?
This has helped some users: https://community.netgear.com/t5/ReadyNAS-in-Business/ReadyNAS-312-Need-Help-Understanding-Snapshots/m-p/936586/highlight/true#M3041
Each snapshot holds the entire share at the time the snapshot was taken - all the files are visible. The reason it is space-efficient is because the data blocks that haven't changed are referenced by both the main share and the snapshots. So unchanged files are only stored once, files that changed once are only stored twice, etc. But they appear in the share and all the snapshots.
There are some shares where snapshots can create problems. Two common examples are shares holding SQL databases that are frequently updated and shares for downloading torrents. The frequent changes result in a lot of snapshot space being used, and also a lot of file fragmentation. Just something to keep in mind.
Note that if you are using Windows 7, 8, or 10, there is a right-click function that shows previous versions of a file. If you are using snapshots, you can right-click on any file in the share (or any folder) and see the previous versions for that file. That simplifies your use-case considerably. (There is a way to turn that feature off if you use custom snapshots).
> Note that if you are using Windows 7, 8, or 10, there is a right-click function that shows previous versions of a file.
> If you are using snapshots, you can right-click on any file in the share (or any folder) and see the previous
> versions for that file. That simplifies your use-case considerably. (There is a way to turn that feature off if
> you use custom snapshots).
Bingo!!!!.... That is what I was looking for: one-stop shopping.
Thanks !!
Glad it helped.
The snapshots aren't continuous, so there are changes that will be missed.
BTW There is a way to install a recycle bin on the NAS (in addition to snapshots) - similar to the feature in OS 4.2. The instructions are old though, and there have been a lot of changes in OS 6 since 2013. So it's possible they need updating.
> Each snapshot holds the entire share at the time the snapshot was taken...
This is looking better and better as I think it through.
I started out thinking only in terms of convenience in restoring a certain file as of a certain number of versions ago - The Windows RightClick to see prior versions being the critical feature for "one-stop shopping".
But now it is starting to dawn on me that the ability to restore an entire share from a given snapshot time/date is a critical feature in event of something like one of those encryption/ransom malware attacks. .... The scenario being that one's 24-7 PC becomes infected, the malware works through that PC's shares into the NAS box to encrypt everything on the NAS, and then the next automated backup cycle backs up all the encrypted files to the backup serve.
In that scenario, onsies-twosies restores would not work - and the single-click restore from the last backup before the infection would save the day.
> Each snapshot holds the entire share at the time the snapshot was taken...
This is looking better and better as I think it through.
I started out thinking only in terms of convenience in restoring a certain file as of a certain number of versions ago - The Windows RightClick to see prior versions being the critical feature for "one-stop shopping".
But now it is starting to dawn on me that the ability to restore an entire share from a given snapshot time/date is a critical feature in event of something like one of those encryption/ransom malware attacks. .... The scenario being that one's 24-7 PC becomes infected, the malware works through that PC's shares into the NAS box to encrypt everything on the "Production" NAS, and then the next automated backup cycle backs up all the encrypted files to the backup NAS.
In that scenario, onsies-twosies restores would not work - and the single-click restore from the last backup before the infection would save the day.
One More Question:
Is there any way to conveniently delete all superceeded file versions before a certain date? ..... or would the backup NAS just keep growing and growing until a Factory Reset/Reload?
PeteCress wrote:
Is there any way to conveniently delete all superceeded file versions before a certain date? ..... or would the backup NAS just keep growing and growing until a Factory Reset/Reload?
If you use the custom snapshots mode, you can set retention (either as a time window or as a number of snapshots). There's also a setting to skip snapshots if the share hasn't changed since the last one was taken - that saves no space, but does reduce clutter on the recover page.. You lose the "thinning" that is done by the "smart snapshots", but from my point of view that isn't really very interesting anyway.
Snapshots will be automatically deleted if the volume gets too full (there is a threshold you can set for that). In the specific cast of a ransomware attack, you have to assume that every file in every share will be re-written. If you use the default threshold of 90%, that implies that you'd need to maintain about 60% free space on the NAS to prevent deletion of the oldest snapshot when the attack hits.
You'd also want to prevent SMB access to the snapshot folders, since of course they could also be encrypted by the ransomware if you don't. That still allows the right-click restore from Windows.
Off-line backup probably needs to be part of this overall picture (since something that's off-line will be safe from any ransomware attack).
>Off-line backup probably needs to be part of this overall picture (since something that's off-line will be safe from any ransomware attack).
Given that I am not ready to double the size of my backup server, I am coming around to thinking that my backup server would best be kept offline and manually booted up only for the duration of each incremental backup.
That would trade the convenience of automated backups and the minor added security of more-frequent backups for the assurance that all would not be lost in a ransomware scenario.
90 percent of my volume is media stuff... The rest (which I think of as "Data") fits easily on the 2-TB disks that I already rotate for daily "Data" backups via Macrium Reflect.....hence "minor"....
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