On 04/16/98 15:48:18 you wrote:
On Thu, 16 Apr 1998, Weeks, Thomas wrote:
RAM on the filer is being run to the very MAX of its specs (maybe more)... I hear that they have a fairly high failure rate on RAM that would otherwise work FINE in slower, less demanding systems (PC's).
'scuse me??? Really? I find this somewhat hard to believe...
60ns RAM is widely available, are you saying they're pushing the envelope on that?
I very much doubt the memory architecture on a NetApp is anything more sophisticated than Sun's memory architecture (and I almost guarantee Sun's memory architecture blows away low-end NetApps)...and Sun seem able to use fairly standard parts without too much failure.
Maybe I'm just missing the big picture...
Part of it is history. Back in the "old days", which is to say only 2-3 years ago in computer time, there were lots of vendors you could get 60ns RAM from that weren't quite up to snuff under heavy loads. And those vendors that did often produced RAM that stood up to their tests, but not to Netapp's. As the industry has progressed, I'm sure today's 60ns RAM chips are of higher quality, so failures may be less common than they once were.
But yes, Netapp seriously pushes the performance of memory under high load, even if that is now more easily within the tolerances of most memory chips.
Another thing to consider is that if you don't run your filers under very high load, it's probably very easy for you to "get away" with lower-quality memory. But don't be surprised if your filer starts getting memory errors once you start running your CPU at 100%, or your cache age at 1, or you have a disk failure and have to do reconstruction while in service, etc.
Bruce
On Thu, 16 Apr 1998 sirbruce@ix.netcom.com wrote:
-On 04/16/98 15:48:18 you wrote: -> ->On Thu, 16 Apr 1998, Weeks, Thomas wrote: -> ->I very much doubt the memory architecture on a NetApp is anything more ->sophisticated than Sun's memory architecture (and I almost guarantee Sun's ->memory architecture blows away low-end NetApps)...and Sun seem able to use ->fairly standard parts without too much failure. -> ->Maybe I'm just missing the big picture... - -But yes, Netapp seriously pushes the performance of memory under high load, -even if that is now more easily within the tolerances of most memory chips.
Oddly, out of our 8 netapps, the only one that hasn't had a RAM or Disk failure is the one with Kingston RAM, Dallas Semiconductor NVRAM and a number of Seagate drives, all sourced as 'third party'.
Of our 4 new f230's we got about 5-6 months ago, we've had one dead NVRAM board, about 2 with bad RAM and I believe 2 ill disks. These are just off the top of my head and possibly not counting the DOA RAM issues and another dead NVRAM board I seem to remember hearing about. Most of these were barely even cracked open by us since receiving them from NetApp but the problems persisted even after reseating, etc.
Humourously, the ones with bad RAM sure worked swell when we stuffed them with cheap Kingston RAM while waiting for the NetApp replacement 'Heavily Tested and Approved' RAM was being shipped.
We paid extra for this?
------------------------------------------------------------- Dave Cole (DC1110) | dacole@netcom.ca Systems Administrator | dacole@vex.net | office/~dacole/ Netcom Canada | www.vex.net/~dacole/ 905 King Street West, Toronto, M6K 3G9 | phone - 416.341.5801 Toronto, Ontario, Canada, Earth, Sol | fax - 416.341.5725
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