Title: Re: [storage-discuss] motherboard for storage server
Eric D. Mudama wrote, On 06/02/2009 02:22 PM:
On Tue, Jun 2 at 12:46, Bob Friesenhahn wrote:
> On Tue, 2 Jun 2009, Roman Naumenko wrote:
>
>> Does it make sense to go with motherboards that support 32G of
memory?
>> Can it improves zfs performance to a significant degree?
>
> The improvement depends on how heavily the server is accessed and
the
> total amount of data which is accessed frequently. With
sufficient RAM,
> the disks will only be accessed for writes and writes will also be
faster
> if the data being updated is cached. If you need performance and
can
> afford it, then go for the 32GB of RAM.
The RAM will be the best performer, but for the cost and power, it
might be a better choice to stick with 8-16GB RAM and add an SSD or
two as a cache device.
Each 4GB FB-DIMM for that motherboard will run you about $100, so a
32GB cache SSD has about the same cost up front as 16GB of RAM. Each
FB-DIMM burns about 10W of power, compared to 2.5W for the entire SSD
when active, and virtually zero when not being accessed.
Well, SDD is interesting thing.
Of course plus-minus 10W or even hundreds W doesn't make any difference
for us, we are not so environmentally friendly here, in Canada as they
try to persuade everybody :) But that the different story.
Regarding SSD. You pointed interesting. And it's particularly
interesting since AVS bitmaps are candidates to be placed on ssd as Jim
suggested recently.
Well, if I want to try SSD, where should I look? Particular
manufactures? Special motherboards? Can you recommend something?
Unfortunately never had experience. And making fast storage appliances
is essential (since reliability is excellent on zfs).
A single cache SSD should be able to easily
saturate gigabit ethernet
even in random workloads if that is your performance bottleneck.
Well, it's a very good speed but I'm afraid with zfs+iscsi it won't be
so fast.
--
Best regards,
Roman Naumenko
Network Administrator
ro...@frontline.ca
25 Adelaide Street East | Suite 600 | Toronto, Ontario
| M5C 3A1
Helpdesk: (416) 637-3132
www.frontline.ca
|
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