[mythtv-users] CentOS vs Fedora, RAID vs LVM

Jean-Yves Avenard jyavenard at gmail.com
Sat Apr 4 21:44:18 UTC 2009


Hi

2009/4/5 David Brodbeck <gull at gull.us>:
> For what it's worth, when copying to a RAID 5 array I often find it's much
> faster to use dd to create a binary copy of the old partition onto the new,
> then resize it to fit the new partition after the copy is done.  (Assuming
> you have a filesystem that allows resizing.)  This is because dd doesn't
> have to do lots of little partial-stripe writes in order to update directory
> entries and the like.

I weighted that decision between using dd and rsync.. And decided on
rsync for two reasons:
1-My existing disk was only 70% full, with dd it would have copied the
whole lot, so copying 600GB of empty data not required
2-as my existing drives aren't healthy, it was likely it could fail
with a read error while copying. With rsync I can restart whenever.

Anyway, it's all completed now...
All I have to do now, is stop all the process accessing the drive ;
re-run rsync once and swap the disk over.

I'm curious on how long it would have taken with dd though


More information about the mythtv-users mailing list