diff options
author | Lars Wirzenius <liw@liw.fi> | 2014-03-29 11:43:45 +0000 |
---|---|---|
committer | Lars Wirzenius <liw@liw.fi> | 2014-03-29 11:43:45 +0000 |
commit | 2dee685a1f8fb954fbeb9fd9a9d0dbb57b34b8ee (patch) | |
tree | cb629d2d27b44eeaae262fbb9975a67048b26317 /manual/en/090-verifiying.mdwn | |
parent | 6d27c778c2c51129d5882c2c5adf2aeac9d36e06 (diff) | |
download | obnam-2dee685a1f8fb954fbeb9fd9a9d0dbb57b34b8ee.tar.gz |
Move English manual texts to en subdir
Diffstat (limited to 'manual/en/090-verifiying.mdwn')
-rw-r--r-- | manual/en/090-verifiying.mdwn | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/manual/en/090-verifiying.mdwn b/manual/en/090-verifiying.mdwn new file mode 100644 index 00000000..7bd2a2d9 --- /dev/null +++ b/manual/en/090-verifiying.mdwn @@ -0,0 +1,58 @@ +Verifying backups +================= + +It's 9 in the evening. Do you know if your backups work? Do you know +when you last made a successful backup of all of your data? Do you +know whether you can restore from that backup? If not, how well can +you sleep? + +You should verify your backups, and do it regularly, not just when you +first set up the backup system. Verification means doing whatever you +need to do to ensure all of your precious data has been backed up +and can be correctly restored from the backups. + +The simplest way to do that is to restore all your data, and compare it +with your live data, and note any differences. That requires you have +enough free disk space to restore everything, but it's almost the +only way to be really sure. + +It's also a great way to ensure the restoring actually works. If +you don't test that, don't expect it'll workd when needed. + +If you have the disk space to do a complete restore, doing so is a +great way to excercise your disaster recovery process in general. +Here's one way of doing it: + +* On your main computer, do a backup. +* On a second computer, perhaps borrowed for this, restore all your data, + without using your main computer at all. +* Start using the restored data as your live data. Do real work, + and do all the things you normally do. Pretend your main computer + was eaten by your pet shark. +* If you notice something missing, or being corrupt, or being too old, + get the files from your main computer, and fix your backup process so + that the next time you won't have that problem. + +How often should you do that? That, again, depends on how you feel about +your data, and how much you trust your backup tools and processes. If +it's really important that you can recover from a disaster, you need to +verify more frequently. If data loss is merely inconvenient and not +life-changingly disastrous, you can verify less often. + +In addition to restoring data, Obnam provides two other ways to +verify your backups: + +* `obnam verify` is like `obnam restore`, except it compares the + backed up data with live data, and reports any differences. + This requires you to trust that Obnam does the verification + correctly. +* `obnam mount` lets you access your backed up data as if it were just + a directory. You can then use any tool you trust to compare the + backed up data with live data. This is very much like doing a + restore, since the comparison tool will have to extract all the data + and metadata from the backup; it just doesn't write it out. + +Both of these approaches have the problem that they compare a backup +with live data, and the live data may have changed after the backup +was made. You need to verify all differences manually, and if the live +data changes frequently, the can be a large number of wrong reports. |