On Tue, Dec 6, 2016 at 2:46 AM, Per Jessen <per@computer.org> wrote:
Greg Freemyer wrote:
Got my Drobo today. So far I'm not impressed.
Pros:
I plugged in 8 1TB drives and it saw them and let me thin provision a 16TB volume.
That sounds like a major pro (or con) - 16Tb with only 8Tb space :-) I guess it automagically dealt with RAID levels and such?
Thin provisioning works like that, and yes as I think about it, it is a major pro. I now have 2 16TB thin provisioned volumes on the Drobo. (The second one eventually provisioned last night.) I can setup several thin provisioned volumes now, then just monitor the overall cumulative disk usage and add (replace) disks as time goes by and needs demand. The user manual does recommend that this particular Drobo only provide iSCSI volumes to one host. It's not a mandate, but it is how the best performance is achieved. Newer / higher performing Drobo's can support multiple hosts. And the FS versions include a true fileserving capability.
I pulled out one of the 1TB drives and popped in my 10TB drive. It recognized it and rebuilt my volume. The rebuild only took a minute or two, but I only have 6GB of data on the volume and it is thin provisioned, so not much data to move around.
Resync'ing 16Gb on plain ol' spinning SATA drives will take a while longer. If the time-to-resync on the Drobo varies with the amount of data, the logic is at a different level. Interesting, I think.
I think that is part of the thin provisioning. As a volume gets filled, more free data blocks are provisioned. When a drive fails, only the provisioned data blocks have to be rearranged. I put 1.5TB of data on the unit overnight. This morning I pulled one of the 1TB drives to see what it will do. SInce I have plenty of spare space on the spindles, A new raid arrangement is being laid down. At the end I will once again be able to handle a drive failure. An hour later, it is still in the rebuild process and the estimate is 12 more hours to complete. Basically it seems I have a choice of configuring the entire Drobo to provide either Raid5 level protection or Raid6 level. The details of how that is handled internally is up to the Drobo.
Regardless, you have to do the initial setup from a Windows / Mac PC.
I probably would not count that as a 'pro'. :-)
Agreed fyi: I now have the iSCSI feature working with Windows 10 as a client. 2 volumes 16 TB volumes provisioned. This Drobo only has 1 1-Gbit port. I'm seeing about 30 MB/sec speeds., but I'm sharing a single NIC on the server, so that's 30MB/sec incoming to the server and 30MB/sec outgoing to the Drobo. 60 MB/sec total. Not too bad for a 1-Gbit port. I'm assuming that single port of the server is the bottleneck. The next step is clearly to move the Drobo traffic onto a dedicated storage LAN. I was a bit frustrated with the unit yesterday, but right now I'm very pleased with it. I will try to provision a volume for an openSUSE box to use and for a Mac to use. That will be for functionality testing, not performance testing. As I said for peak performance I need to establish a dedicated storage LAN. which doesn't carry any front office traffic. That will take a week or so to setup since I need to get a few miscellaneous parts. Greg -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org