UFS dump/restore missing files

uzsolt

Well-Known Member

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I want to use dump() and restore(). But I think I don't understand well something.
I ran dump -0 -C16 -Laf /home/backup/hdd/dumps/ssdhome.dump /dev/gpt/ssd-home - after ls in restore -f /home/backup/hdd/dumps/ssdhome.dump -i - it's okay.
Incremental dump after some seconds: dump -1 -C16 -Laf /home/backup/hdd/dumps/ssdhome.dump /dev/gpt/ssd-home
I tried ls again and many files and directories disappear in dump.
The /home/backup/hdd is other file system than /dev/gpt/ssd-home.

What happened?
 

ANOKNUSA

Aspiring Daemon

Reaction score: 372
Messages: 675

Just for the sake of clarity: https://en.wikipedia.org/wiki/Incremental_backup ;)

When specifying a level higher than 0 in dump(8), only the files that have changed or been added since the last backup of the next-highest level are copied. So a level-1 dump will only contain files that have changed or been added since your most recent level-0 dump, and a level-2 dump will only contain files that have changed since the last level-1 dump. Moreover, you gave your level-1, incremental dump the same path and file name as your level-0 dump--so you overwrote the original. You'll want to give your incremental dumps incremental names--ssdhome_0.dump, ssdhome_1.dump, and so on--or append days/dates to the file names.

Personally, I recommend just doing level-0 dumps if possible. It avoids the hassle of organizing complex backups, and restoring a single level-0 backup is painless compared to restoring several incremental backups on top of each other. I run a level-0 dump on about 150Gb of data every day--the backup takes less than 30 minutes.
 
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uzsolt

uzsolt

Well-Known Member

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Messages: 269

Ah, I thought the level-1..9 dump appends to the dumpfile. As I see dump knows about newer files from /etc/dumpdates.
I think I understand the mechanism :)
Thanks!
 

kusanagiyang

Member

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Messages: 30

Hello,
I can't wrap my head around the Hanoi sequence used in the man of dump.
Normally for me, an incremental dump just goes into sequence; level 2 backs up everything newer after a level 1, and level 3 backs up everything newer after a level 2, and so on so forth.
If I need a file dumped at level 3, I need restore 0, 1, 2, 3 in order to get it, right ?

I have googled up and down for explanations why the Hanoi sequence works when dumping to no avail...

Can anyone help me understand this ?

www.nncron.ru/nnbackup/help/EN/working/modes/dump.htm
 
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