On Tue, Sep 05, 2006 at 12:23:08PM -0400, Ian Turner wrote:

| On Tuesday 05 September 2006 05:21, Phil Howard wrote:
| > On Mon, Sep 04, 2006 at 11:01:20PM -0400, Ian Turner wrote:
| > | On Saturday 02 September 2006 16:21, Phil Howard wrote:
| > | > It would not need to be separate for each OS.  The idea of using a
| > | > partition table isn't even the only approach.
| >
| > If all that is written is tar format, nothing more needs to be added.
|
| Ah, but if you ditch the partition table, then indeed more needs to be added.
| How else would you tell the end of one dump from the start of the next?

That would indeed be a limitation.  Using partitions would be better.  Not
doing so could still be an option for those that know they have no need to
do more than one dump per media.


| > I didn't keep any stats, or really do it scientifically.  Someone that
| > wants to should probably control for a lot of the variables that influence
| > it. But I do recall the speed improvement is about 25% to 30%.  I suspect
| > much of that is OS work bypassed with O_DIRECT.
|
| I suspect you incur a substantial performance penalty if other processes are
| using the disk concurrently, because then you only get one write() per
| elevator traversal.

The disk being used for backup would have to be dedicated.  You could get
away with doing it all entirely inside one partition of a non-dedicated
disk.  But I'm focused on the backups that go to external media, which can
be a real tape, if tape were a viable option, or to an external SATA disk
in a separate disk enclosure, plugged in as needed.

-- 
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| Phil Howard KA9WGN       | http://linuxhomepage.com/      http://ham.org/ |
| (first name) at ipal.net | http://phil.ipal.org/   http://ka9wgn.ham.org/ |
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