PE6850 recommendations

Richard Ford rford at candis.com.cn
Mon Feb 12 04:07:31 CST 2007


For RAID 10 you need even disk numbers greater than 4.

So with your current 5 disks you can have a RAID10 and a hot spare.   
This will only yield 146GB of space however.

Most anecdotal evidence that I have seen suggests that with SCSI (not  
sure about SAS) 4-5 drives will saturate the bus.

I would look at an option for front bay drives and mix raid - so the  
OS can be seperate to the data.  Not sure about Oracle, but with  
postgresql I have the transaction logs (which are used before  
commits) on the system drives and the database on a PV220S with  
RAID10 over two channels using split bus mode.  The speed is AWESOME!

So I would look for a RAID1 + ( RAID 0 (RAID1 + RAID1)) setup.  This  
will require two perc cards though and the right back plane.  But if  
you split the main 10 drive bay back plane into two and then make  
your raid 1 sets using sets that straddle the split backplane before  
spanning, then the speed is increased and the channel redundancy too.

I would use, 2 x 36K 15K drives for OS in the front bay.

Then 4-6 15K 146 or 73GB drives in the main bay using a split backplane.

Cheers,
RF.


On 12 Feb 2007, at 3:56 PM, Mad Unix wrote:

> so I think I would go for RAID10, can you tell me if the requested  
> Hardware spec
> can do that, fell free to modify my spec, and let me know pls
>
> Thanks 10000x in advance.
>
>
> On 2/12/07, Richard Ford <rford at candis.com.cn> wrote:
> G'Day,
>
> I have one run for a client like this for two years with good
> results, 1 one year centos4 and one year with esx3
>
> 2 x 3.16Ghz MP CPU
> 4  x 1GB RAM
> Front Bay Hard drives with 2 x 36GB 15K U320 SCSI
> Main Bays with 9 x 73GB 10K U320 SCSI - in RAID 50  with global hot
> spare.
> Redundant Power
> DRAC Card
>
> The main issue we had was power, the thing need big power plugs (3
> amp) and good power source, we had to have the clients data room
> redone with more power points of the right type (forget the name -
> but damn huge industrial plugs) and power conditioners
>
> The other issue was disk IO.
>
> RAID 5 with 8 disks was just crappy.
>
> RAID 10 was much better but we needed more space in the end because
> when we specced storage we had RAID5 in mind and many spindles.....
>
> RAID 50 seems to be almost as fast as RAID10 and has heaps more space
> and we are very happy with it and the PERC4 on this server.
>
>
> Cheers,
> RF.
>
> On 12 Feb 2007, at 2:55 PM, Mad Unix wrote:
>
> > I want to build a Server using PoewrEdge 6850 running raid 5 or
> > raid 10 (didn't decide till now about raid config)!
> > the server will be a web server with DB running RHEL4 and Oracle,
> > please can you tell me if my proposed technical spec would be okay
> > and run smoothly with Redhat, such as
> > Hard Drive Configuration,Hard Drive Back plane,Primary
> > Controller,Primary Hard Drive, RAID10, RAID5, No. of the hardisks
> > and volume..etc
> >
> > DELL PowerEdge 6850 Technical Specification
> > Processors New Dual-Core Intel®  Xeon® MP processors, Dual Intel
> > Xeon processor upgradeable to Quad on motherboard;
> > with the following options of processor speeds·
> > Dual Core Intel® Xeon® Processor 7140M, 3.4GHz, 16MB L3 Cache,
> > Front Side Bus 800MHz front side bus
> > Chipset Intel ® 8501
> > Memory   16GB DDR2 SDRAM expandable up to 64GB
> > Hard Drives 5 X 73GB (15,000 rpm) Serial Attached SCSI SAS Hot
> > pluggable hard drives
> > Drive Controller Dual channel integrated SCSI controller.
> > RAID Controllers Embedded Dual Channel RAID Controller: SAS 3.0 Gb/
> > s with 256MB battery-backed cache supports all RAID Levels
> > Graphics Integrated ATI-Radeon 7000 with 16MB of SDRAM
> > Optical Devices: DVD/CD RW combo Drive.
> > Drive Bays Internal hard drive bay to support up to five 1" SAS
> > SCSI hard drives
> > Expansion Slots & I/O Slots 7 total I/O slots on 3 PCI buses4 hot-
> > plug PCI-Express slots (one x8, three x4)1 hot-plug PCI-X slot (64-
> > bit/133MHz), 2 non hot-plug
> > Ports Rear: (2) USB 2.0, (1) 9-pin serial, (1) video, (1) ID push
> > button with blue/amber LED Front: (2) USB 2.0, (1) ID push button
> > with blue/amber LED, (1) 15-pin video, system power on/off button
> > Communications Embedded Dual Gigabit Ethernet controller  
> (10/100/1000)
> > Compatibility  Red Hat® Enterprise Linux® 3 and 4; SUSE® Linux
> > Enterprise Server 9 EM64T SP
> > Power and Cooling 1,470W, hot-plug redundant power, 200-240 Volts
> > only with Hot-plug, redundant cooling fans
> > Chassis   Rack-mountable Chassis 4U
> > Country of Origin Main System Ireland
> > Warranty  Three Years on-site (Parts & Labor)
> >
> >
> >
> > any comments would be really appreciated.
> > --
> > madunix
> > _______________________________________________
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>
>
>
>
>
>
>
>
> -- 
> madunix





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