Sun 6140 and CAM is something I don’t understand

I still consider myself a newbie when it comes to Sun / StorageTek’s 6140 array and the Common Array Manager (CAM) software used to configure it. I’ve done a 3 day course and about 5 implementations now, but I just don’t have a handle on it like I do with the EMC CLARiiON. There are a lot of things I like about the 6140 (which is a rebadged Engenio 3992 or 3994 depending on whether you bought the lite version or not). You can intermix FC and SATA in the same tray – something that EMC don’t seem to be able to do you yet (if you ignore the LC-FC debacle that went to market with the intitial range of CX3 trays). It’s a robust array, with lots of storage capacity and a reaonable (for mid-size deployments) amount of cache. Connectivity options are fairly flexible. Firmware upgrades are a total doddle compared to the ugliness that is a FLARE upgrade on a CLARiiON (although EMC have worked pretty hard at streamlining that process). My general feeling is the array just runs, and runs pretty well.

That said, there are still some things I don’t like about it, and most of those are CAM-related. I think it’s insane that Sun are pretending that SANtricity never existed – because it actually works really well. Until recently CAM’s remote monitoring didn’t actually work, even though it was a configurable option, leaving a few customers with orange lights on the array and wondering why Sun hadn’t called. CAM itself is a pig to install unless you’re sitting on a Solaris server. It still doesn’t support Internet Explorer 7 (according to the release notes for 6.00.10), although it does actually work, just not quickly. The install scripts often bomb out at random points in the process with cryptic or non-existent error messages, leaving me looking like a knob in front of the customer, who just payed a lot of money for some tin with fairly crappy management foo over the top of it. I think the fact that I have to install off-array management software is just silly anyway, having been spoilt by Navisphere Management Server on CLARiiONs for the past few years. Yes, I know, EMC want you to install service taskbars and so forth nowadays, but you can still log directly into the array using a laptop, with no need to go dicking about on the customer’s infrastructure.

CAM also uses “industry-standard” methodologies for storage provisioning, and thus a RAID Groupis a Virtual Disk, a LUN is a Volume, a Storage Group is a Host Group, and I still have to manage initiators manually. My colleague, who has worked on much more Engenio kit than I have, assures me that this is, indeed, the way it is done. But if I was being catty, I’d say something like “EMC ownz the mid-sized market, therefore what they do is the industry-standard”. But I think it’s just a matter of whatever you learnt first will seem the most comfortable. The rest of my problems seem to be related to Sun as an organisation. It’s hard to find information on deployment and configuration on the site, the documentation is lite, to say the least, and the general approach seems to be, let’s just sell a lot of them and see what happens. I’m sure that’s not really the case, but I seem to have an easier time getting the necessary information out of EMC when it comes to “things I need to know to not look like a tool in front of the customer”. And I don’t like that we position it as a 4Gbps back-end, when that requires a suitable drive configuration to actually work, although EMC have had a similar problem with SATA until SATA-II came out.

Anyway, the point of this diatribe was to pose a question to all three of my readers. Why is it, when I perform a dynamic expansion of a RAID-5 virtual disk, that I can only add 1 or 2 disks at a time? I recently added 3 FC disks to our array and wanted to perform a dynamic expansion. I worked it out, but I want to know why it behaves that way. I can’t find the information anywhere, and my sunsolve account doesn’t have a valid contract at the moment. Oh, and season’s greetings.