On Wed, 2002-11-13 at 16:11, Sherman Boyd wrote:
> Hi,
>
> I've been using the NetVault backup application to back up my Linux boxes
> running XFS over the network. Everything is very fast, except restores crawl
> along at about 21 kb per second. The guys at NetVault said that it was
> because
> I have a journaling filesystem, and suggested that I turn off journaling (if
> possible) while I am restoring a backup. This seems strange to me and brings
> up
> some questions:
Maybe it is because netvault does not know how to use a journalling
filesystem. Unless we know how it is writing data into the filesystem
I am not sure we can do much here. My bet is that it is opening files
O_SYNC and doing small writes. You could attach strace to the process
doing the writing (or one of them) and send a sample of its output.
>
> 1) Does anyone else experience this kind of an issue using any other backup
> application?
>
> 2) Can I turn off journaling in XFS temporarily to resolve this, and would I
> want to?
No you cannot.
>
> 3) Why would journaling affect the speed of restores and not backups?
>
backup is a readonly operation, restore is a write operation, only
the latter involves the journal.
> Thanks for reading this and thanks to those that develop XFS,
>
> Sherman Boyd
> meekrob@xxxxxxxxxxx
>
Steve
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