Archive for the 'DAS' Category

In case you’re wondering…

Friday, May 27th, 2011

Point of reference – A few months ago I wrote a post that I never ended up publishing that started with the line:

“My gods I need to work with technology that wasn’t conceived of in the 1990s.”

With that in mind, in case you’re wondering where I’ve been this past month or so…

I’ve been playing with this beast…

8 Engine VMAX

225 400G SSD Drives (90 TB Raw)

Direct Attached to *ONE* host.

Biggest.  Thumbdrive.  Ever.

Well I was saying I needed to get some serious hands-on VMAX experience.  When you put a request like that out there, sometimes the universe answers LOUDLY. ;-)

So much fun, so little time.

Friday, April 11th, 2008

A few have noticed the site was down for an extended period this week.  I learned a few things this week.

I set up my FC system and was so excited to get it moving that I neglected to adequately test my equipment.  I bought used equipment, with used drives, and put real data on them after a whopping 2 days of light testing.  I never stress-tested the drives, didn’t do any kind of exercizing of them to validate that they were worthy of production data.

I also neglected to functionally test the array.  While it did offer the ability to configure a hot-spare, I didn’t check to see if the hot-spare was functional before I moved data over to it.  (Seeing that it was configured was enough for me)

So what happened was this.  I was running on the system and all was well until a drive failed.  The hot-spare didn’t invoke on it’s own, and while one drive was in a failed state, the second drive failed.  Needless to say I lost half my luns and three of them were corrupted beyond repair. 

Luckily I’m one of the old hold-outs.  I have a tape backup system consisting of a Veritas 6.0 environment with an ATL tape library.  I was able to restore to within 48 hours of the failure using tape.

My *NEW* storage back-end of consists of a Dell 2650 with 5x 146G drives.  I installed CentOS5 with a 512GB NFS-mount partition and mounted them to my VMWare servers.  The most interesting part is I realized that by bonding the network interfaces I’m getting the same bandwidth I got out of the 2x 1Gig fibrechannel ports.

Not being a network guy though, does anyone have any suggestions for optimising NFS for storage applications?

MS Exchange 2007 disk Requirements

Wednesday, May 23rd, 2007

I got it from two very reliable sources that MS is recommending that best prcatice for Exchange 2007 is that it should be on RAID 1+0 (fair enough), but that it should also only be hosted on DAS.
What is the your (and the SAN community’s) perspective on this?
Is this only for very large user bases? Does this mess up some of my Clariion plans?
Have we finally found a use for SAS shelves?

Thanks