Thanks Paul : Re: Which RAID will be better solution?

Hi Paul,
Thanks very much for your exhaustive info. I will have to go throufh it peacefully. But honestly, i have not understood the term 'Hot-sparing and hot-swsapping'. Can you please simplify it for me. Thank-U,
Ravi.

>From: Paul Drake <paled_at_home.com>
>Reply-To: ORACLE-L_at_fatcity.com
>To: Multiple recipients of list ORACLE-L <ORACLE-L_at_fatcity.com>
>Subject: Re: Which RAID will be better solution?
>Date: Sat, 24 Jun 2000 00:32:30 -0800
>
>Ravi Babu wrote:
> >
> > Hi Friends,
> > I want to do RAID configuration for a database which is high OLTP
> > environment. 50-60 users are connected at a time. Performance is very
> > important. How many disk arrays will be better?
>
>MORE! 8)
>
>I saw a decent article on Dell's Website in the Power Solutions
>Magazine.
>(yes, Hi - I deploy/maintain Oracle Servers on WinNT at remote Client
>Sites.
> Someday, I may be an Oracle on Unix bigot also ... but for now, NT)
>
>http://www.dell.com/us/en/biz/topics/power_ps3q99-raid.htm
>
>Both the Oracle 8i DBA Handbook and the Oracle 24 x 7 book (Oracle
>Press) have good discussions concerning optimal layouts.
>I believe that their dream system had 21 drives on independent
>controller channels -
>
> 14 drives is where they started waking up ...
> and 7 drives is where they started to get reasonable.
>
>RAID 5 can bite you. It bit me 2 weeks ago.
>I'd avoid it except for read-only tablespaces.
>That leaves RAID 1 and RAID 10.
>Sure, I run RAID 0 on my workstation, but I take incremental backups
>every night, full on weekends.
>
>Performance will seem most important, until you try to recover the
>database.
>Design it with fault-tolerance and recovery in mind, first.
>
>Is this Standard Edition or Enterprise Edition? Version? Platform?
>
>1. Hot sparing
> - are you planning on just hot-swappable, or will you be hot-sparing?
> - if you are hot-sparing, each channel needs its own spare
>2. Backups to disk - will you be backing up to disk before copying off
>to tape?
>3. Backup strategy
> - will you be performing a full logical export before the cold backup
>each week?
> - will you be performing cold backups over the weekend?
> - will you be performing hot backups during the week?
>4. will read only tablespaces be used? Big reduction in backup space
>requirements.
>5. do you plan on duplexing the online redo logs?
>
>A simple Intel based system is as follows:
>
>Pair of 866 PIII CPUs
>lots-O-RAM - say - 2 GB. when you pay by the power unit,
>2 (triple or quad)-channel RAID controllers (need 4 external channels)
>Internal cabinet split backplane.
>2 External storage cabinets with split backplanes.
>cabling
>18 GB Ultra 160/m drives (good price point these days)
>volume RAID drives storage (GB) contains
>0 1 2 17.4 OS, Binaries, SYSTEM, swap
>1 1 2 17.4 online redo, archlogs
>2 1 2 17.4 indexes, dumps
>3 1 2 17.4 temp
>4 1 2 17.4 rbs
>5 10 6 52.2 user_data
>
>If you're configuring with Parallel server in mind, I'd put the
>OS/binaries and log files in the internal cabinet. The second instance
>can mount the index and data files in the external cabinets.
>
>64 bit, 66 MHz, multiple PCI bus mainboards are the way to go.
>
>Remember, disk I/O is only part of it - front side bus means alot too -
>PC 133.
>Quad-port Fast Ethernet or Gigabit Ethernet is also a factor.
>You wouldn't spend all that on disk I/O only to have 1 10/100 NIC, would
>you?
>
>If you want to speed up RBS or Logs, set them up as RAID 10.
>Will you be using a write-back cache setting (battery on the controller
>card + UPS)?
>Some people recommend the use of solid state drives for the online redo
>logs for speed.
>If you do - duplex them.
>18 GB drives were chosen just for minimizing the number of spares
>needed.
>'Extra' room will serve well as staging areas for hot/cold backups to
>disk.
>
>Most likely, you won't be using swap at all.
>
>If you run the datafile_IO scripts - you'll have a better idea which
>tablespaces have the most read/write I/O. If you have to start
>condensing datafiles onto volumes, you'll be able to make an informed
>decision as to which to put together.
>
>
>So there's a start.
>
>Paul
>--
>Author: Paul Drake
> INET: paled_at_home.com
>
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