Hello --
Thank you very much for your input. The summary is basically, "What, are
you crazy? Do disk to disk." Many people also felt the ratio is 1:3 or
1:4, depending on file size and type.
Thanks again for your help. You guys are great.
The replies excerpted below are samples of what everyone basically said.
Donn Aiken Applications Engineer Regents College
daiken_at_regents.edu
http://www.regents.edu
These comments are my own and do not necessarily reflect the policies or
position of Regents College.
>From klarsen_at_enterprise.afit.af.mil:
Yes, the ratio holds at ~ 1:3 or 1:4. I would do disk-disk but use
dd instead of dump. That way you should not need comversion of any
kind and it should be quicker.
>From Vinzenz_Esser_at_emass.com
If your SCSI configuration (sufficient available target & lun numbers)
allows for having the old and the new raid array connected to the system at
the same time, then the quickest way to bring the data over is copying it
directly from the old to the new disks.
You'd want to use the vdump/vrestore commands for this. Here's an example:
# vdump 0f - /oldraid | vrestore -xf - -D /newraid
This will copy everything underneath /oldraid directly to /newraid. You'll
obviously have to replace /oldraid and /newraid with the directory names
that apply for your installation. /newraid will probably be a temporary
mount point until all the data has been copied over and the old raid array
has been removed from the system.
Repeat this command sequence for every mount point you have on the old raid
array. To speed up the whole process even more, you'd also want to consider
running multiple vdump/vrestore procedures simultaneously, if the source
for the different vdumps is coming from separate disks inside the raid
array.
I've used this approach numerous times and it has never caused any
problems. And it's CONSIDERABLY faster than restoring everything from tape.
But then you'd also want to backup to tape before starting the
reconfiguration job as an additional safety net.
Hope this helps,
Vinzenz
Received on Wed May 13 1998 - 20:44:47 NZST