Older SAS1 hardware Vs. newer SAS2 hardware
By Steve Tunstall on Jun 21, 2011
I got a question today from someone asking about the older SAS1 hardware from over a year ago that we had on the older 7x10 series. They didn't leave an email so I couldn't respond directly, but I said this blog would be blunt, frank, and open so I have no problem addressing it publicly.
A quick history lesson here: When Sun first put out the 7x10 family hardware, the 7410 and 7310 used a SAS1 backend connection to a JBOD that had SATA drives in it. This JBOD was not manufactured by Sun nor did Sun own the IP for it. Now, when Oracle took over, they had a problem with that, and I really can’t blame them. The decision was made to cut off that JBOD and it’s manufacturer completely and use our own where Oracle controlled both the IP and the manufacturing. So in the summer of 2010, the cut was made, and the 7410 and 7310 had a hardware refresh and now had a SAS2 backend going to a SAS2 JBOD with SAS2 drives instead of SATA.
This new hardware had two big advantages. First, there was a nice performance increase, mostly due to the faster backend. Even better, the SAS2 interface on the drives allowed for a MUCH faster failover between cluster heads, as the SATA drives were the bottleneck on the older hardware. In September of 2010 there was a major refresh of the rest of the 7000 hardware, the controllers and the other family members, and that’s where we got today’s current line-up of the 7x20 series. So the 7x20 has always used the new trays, and the 7410 and 7310 have used the new SAS2 trays since last July of 2010.
Now for the bad news. People who have the 7410 and 7310 from BEFORE the July 2010 cutoff have the models with SAS1 HBAs in them to connect to the older SAS1 trays. Remember, that manufacturer cut all ties with us and stopped making the JBOD, so there’s just no way to get more of them, as they don’t exist. There are some options, however. Oracle support does support taking out the SAS1 HBAs in the old 7410 and 7310 and put in newer SAS2 HBAs which can talk to the new trays. Hey, I didn’t say it was a great option, I just said it’s an option. I fully realize that you would then have a SAS1 JBOD full of SATA drives that you could no longer connect. I do know a client that did this, and took the SAS1 JBOD and connected it to another server and formatted the drives and is using it as a plain, non-7000 JBOD. This is not supported by Oracle support.
The other option is to just keep it as-is, as it works just fine, but you just can’t expand it. Then you can get a newer 7x20 series, and use the built-in ZFSSA replication feature to move the data over. Now you can use the newer one for your production data and use the older one for DR, snaps and clones.