We have "raid swap"ed almost three shelves worth of drives into an F330 at one time. The AE recommended this method as being faster than installing all the drives at config time and building that large file system from scratch. This worked fine, but still takes a significant amount of time.

We later added a fourth shelf and "raid swap"ed all those drives in at once. The filer was only off the net for the length of time it took to halt/connect the SCSI cable/ reboot. A few hours later, after the raid swap completes, all the additional disk space shows up - it does not show up one drive at a time.

Some comments regarding DLT drives - I have heard that you want to keep them "streaming" (feed with data) or the drive has to stop, wait for data, backup, reseek to the stop point, and start again. This applies to both 4000/7000 series. You pay a significant speed penalty for dropping the drive out of streaming mode. Our word from Netapp is that for an F230, they sell the FW/DIff card and it works, but it is not officially QA'd in the system, but soon should be.

Our performance on an F330 using Budtool backup and NDMP locally attached DLT4000's ranges from 1-3MB per second overall throughput, and most of the time it is about 2.2MB per second. This number is averaged over the entire backup set (all data on the disk array).

I'm not an expert on any of this, so check with the vendors to verify if it doesn't sound right...

----------------------------- sirbruce@ix.netcom.com wrote:

On 10/07/97 21:12:31 you wrote:

...

Can you "raid swap" and add more than one spare disk at a time?

No... you want to raid swap, shove a disk in, wait for it to detect, raid swap again, shove another disk in, etc.

The fastest way to do lots of disks at once is to halt and power off the filer, shove the disks in, and then turn it back on.

Bruce