>
> The common wisdom is that dump is dangerous to run on mounted
> filesystems. I do so for weekly backups
> on my home system, because it is scheduled for 2AM on Sunday morning, when
> things are relatively idle.
> I note from the man pages that xfsdump can only be run (apparently) on
> mounted filesystems. Is there
> anything fundamentally different about the implementation of xfsdump (for
> linux specifically) as opposed to the
> other dump programs (such as for ext2 filesystems) that makes this "safer"?
>
xfsdump does not use the block device interface to get to inodes, it
uses a couple of special calls - one to scan all the inodes in the
filesystem and one to open those inodes without using path names,
should an inode change in between the two accesses then it is not
placed in the dump. File data is read using the read system call,
directory contents via getdents.
So there is no issue with xfsdump looking under the covers the way the
regular dump program does. There is an issue with xfsdump missing files
created during the dump process - but the next dump should catch those.
Steve
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