We have been using an ADIC Scalar 218 for some time with our F740 cluster with fairly good results until recently. Our Netapps provide the storage for our Web and Mail clusters. We have experienced pretty serious growth and are seeing some significant slow downs in backup turnaround time. We have up until this point also just been backing up the data over NFS mounts to our NetBackup server. Being that most of the data comes from the mail server side and we use maildir, it is not a huge amount of data but is a huge number of smaller files. I'm not very confident that NDMP would completely correct the problem, but it seems that removing the network/nfs overhead couldn't hurt. I think I have made the decision to go with the ADIC Scalar 1000 with 2 drives dedicated to the Netapps (1 to each in the cluster) with NDMP and 4 more drives dedicated to the backup server for other systems.
2 questions:
1) What are some impressions on NDMP as a performance gain for backups? Right now the network does not seem to bottleneck the process as we have dedicated 100m links from the servers to a separate NFS/backup network, and 4 channel etherchannel from each netapp to that same network. From MRTG graphs this network is mostly idle (10-20m max) even during backups. I don't appear to be able to keep the DLT's saturated (in other words the activity light doesn't stay on the whole time, so it is not streaming non stop) during backups, and I don't know if this is NFS overhead, or there is another problem. Is NDMP more capable of keeping a DLT fully saturated and therefore more efficient, or do I still need to look at this as a Netbackup issue?
2) A little OT but - Does anyone have any good experience with this particular library (ADIC Scalar 1000)? I loved our smaller Scalar.. but have more long term experience with StorageTek. My salesperson has done a good job convincing me of the advantages of this box, and I am pretty much sold. Just curious if anyone else has any horror stories or glowing recommendations.
Eric Hester Director of Systems Engineering NuVox Communications eric@nuvox.net