Linux - ServerThis forum is for the discussion of Linux Software used in a server related context.
Notices
Welcome to LinuxQuestions.org, a friendly and active Linux Community.
You are currently viewing LQ as a guest. By joining our community you will have the ability to post topics, receive our newsletter, use the advanced search, subscribe to threads and access many other special features. Registration is quick, simple and absolutely free. Join our community today!
Note that registered members see fewer ads, and ContentLink is completely disabled once you log in.
If you have any problems with the registration process or your account login, please contact us. If you need to reset your password, click here.
Having a problem logging in? Please visit this page to clear all LQ-related cookies.
Get a virtual cloud desktop with the Linux distro that you want in less than five minutes with Shells! With over 10 pre-installed distros to choose from, the worry-free installation life is here! Whether you are a digital nomad or just looking for flexibility, Shells can put your Linux machine on the device that you want to use.
Exclusive for LQ members, get up to 45% off per month. Click here for more info.
The advantage of using snapshots as the means to get a backup is best seen for applications such as databases where you can greatly reduce the time the database is offline for a backup. For filesystems, it is not as clearcut as if you don't quiesce the filesystem during the snapshot, all you are guaranteed is a crash-consistent image of the filesystem.
As far how secure a snapshot is as a backup, it is directly related to the robustness of your storage back end. Maybe it is best to think of a snapshot as short term data protection, with migrating it to long term storage as an option.
forbin, I agree LVM snapshots are not the solution in and of itself for daily/weekly backup or archiving. But, they definitely are a valid means to get there or to provide short term protection against data corruption. Taking a snapshot before performing a database upgrade, so that you can revert the database if anything should happen is one example of using a snapshot for short term protection.
I see your viewpoint, but I just don't think it qualifies as a backup. That's why all the examples you find on the internet of "how to use LVM snapshots to take a backup" have at least two steps. The first step is to take the snapshot. The second step is to take a backup of the snapshot using tar or something else. (And then a frequent third step that people often suggest is to destroy the snapshot.) Using snapshots alone, I think you end up with a false sense of security. When your "original" and your "backup copy" actually point to most of the same disk sectors, you have a fundamental problem. I can understand why snapshots might be sufficient for some people, but they sure don't work for me.
I see your viewpoint, but I just don't think it qualifies as a backup. That's why all the examples you find on the internet of "how to use LVM snapshots to take a backup" have at least two steps. The first step is to take the snapshot. The second step is to take a backup of the snapshot using tar or something else. (And then a frequent third step that people often suggest is to destroy the snapshot.) Using snapshots alone, I think you end up with a false sense of security. When your "original" and your "backup copy" actually point to most of the same disk sectors, you have a fundamental problem. I can understand why snapshots might be sufficient for some people, but they sure don't work for me.
That's why I take my snapshots, backup to tape and then store all of the tapes in a cardboard box next to a kindling, fireworks and nitro-glycerine factory. Superb.
That's why I take my snapshots, backup to tape and then store all of the tapes in a cardboard box next to a kindling, fireworks and nitro-glycerine factory. Superb.
LinuxQuestions.org is looking for people interested in writing
Editorials, Articles, Reviews, and more. If you'd like to contribute
content, let us know.