Raid-0 to Raid-5 possible without loosing data

I have a Raid-0 striped volume on two 300GB hard drives, which gives me
a 600GB drive. I'd like to buy a new 300GB additional drive and run
Raid-5 instead. Is this possible without loosing the data or do I have
to delete the Raid-0 loosing all my data and make it Raid-5 instead?

I use Silicon Image SATA Raid SiI3114 which comes with my motherboard
ASUS A8N SLI Deluxe.

In article .com,
"Niklas Engfelt" wrote:

I have a Raid-0 striped volume on two 300GB hard drives, which gives me
a 600GB drive. I'd like to buy a new 300GB additional drive and run
Raid-5 instead. Is this possible without loosing the data or do I have
to delete the Raid-0 loosing all my data and make it Raid-5 instead?

I use Silicon Image SATA Raid SiI3114 which comes with my motherboard
ASUS A8N SLI Deluxe.

Would you use this tool on a live system ? I wouldn't.

http://www.gamepc.com/labs/view_cont...=r52005&page=7

I'd be tempted to buy 3x300GB and set up an independent RAID
array. You could use your stripe as a backup set, then unplug
them when you are finished. Presumably that would mean using
the Nvidia controller for part of this operation.

With five drives I would try:

1) Install a new pair of disks on Nvidia. Set up in RAID 0 and
copy the SIL3114 RAID 0 pair to the Nvidia RAID 0 pair.
2) You could experiment with in-place migration on the SIl3114,
knowing you have a backup on the Nvidia striped pair. That is,
assuming you can find the option in the manual or the interface.
3) If not (2), then with the backup in place, delete the array
on the SIL3114, and add the third disk. Copy the Nvidia
RAID 0 stripe over to the SIL3114 RAID5 three disk array.
4) Disconnect the RAID 0 Nvidia array, and save it for the
occasional backup.

According to the SIL3114 manual, their software supports what
they call "roaming", implying it is what others call "migration".
But since this option is never explained elsewhere in the manual,
I cannot be sure it is even there.

In any case, I'm a "safety first" kind of guy. Doing "migration"
without a backup, is like doing brain surgery on the side of the
highway, with a rusty knife :-)

You also have the option of doing RAID 0+1, which would take
four disks arranged as two RAID0 arrays, mirrored against
one another. That gives you good read and write performance,
while the write speed on the RAID5 could be pretty bad. But
then, you still don't have a backup strategy, and just because
you have some redundancy in an array, doesn't protect you
against the PSU putting out a high DC voltage and burning all
the drive controllers at the same time. That is why I like to
disconnect backup disk drives (your Nvidia RAID0 pair could be
put in trays, and removed from the computer for storage
elsewhere).

On page 12 of the gamepc.com review it says:

"In comparison, the Silicon Image and 3Ware controllers give
fairly abysmal write speeds, ranging from 5 MB/s to 15 MB/s."

Your SIL3114 will make a fine array for playback of streaming
content (music or video), but might make a pretty miserable
general purpose R/W array.

Paul

Thanks for the tips and ideas! I guess buying 2 new hard disks is my
option or buying 1 and reduce my content to 200GB (my external drive)
to be able to transfer it back and forward while rebuilding the raid.