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Re: Optimal hard disk layout for Oracle

From: Paul Drake <>
Date: Sat, 02 Sep 2000 02:06:41 -0400
Message-Id: <>

Caution: NT on Intel bias present - but I'm trying to outgrow it. context: 4 CPUs max. and NO RAID 5.

Imagine for a moment that you have a fixed budget to devote toward an Oracle Server.
This amount includes your Oracle licensing, OS, hardware, etc. also assume that your site doesn't have a site license, but is stuck paying by the *Power Unit*.
Enterprise Edition $100/MHz (list), think twice before salivating over 1 GHz Xeons.
Standard Edition $15/MHz (list) - 4 x 700 MHz x $15/MHz = $42,000.

Figure on     $500 per I/O channel for Dell, $1000 per I/O channel for Compaq.
Figure on     $500 per 18 GB drive for Dell, $1000 18 GB drive for Compaq.
Yes, its likely that you won't even need 25 % of the space on these drives. Storage is relatively cheap, Power Units are relatively expensive.

Strategy 1. Hold the Wintel Line - MHz is king, single I/O channel. throw as much Mhz and RAM at is as possible. Single Fast Ethernet Card, Network tape drive. No recovery accelerators installed.
Vendors love this, as they make a premium on 4 and 8 way CPU boxes. Companies like it, as need for proper tuning can be ignored - paper DBA can administer system.
Single RAID 5 array, based only on size of storage needed. Write back cache, no UPS.
Recovery time not an issue, as this company hasn't had a recent crash. One can only tell the system is I/O bound if you know enough to look. Since Oracle is billing by the MHz, this is good business. "We don't need no stinkin' OFA."
Never tested backup/recovery strategy, using logical exports, fortunately. Performing nightly backup of an open database, the Cluetrain hasn't stopped here yet.

Strategy 2. Read the OFA doc - desires minimal seek time - higher concurrency. deploying box that can only store 10 internal drives, e.g. Dell PowerEdge 4400 Box has 3 I/O channels - removable bay cage (2 drives), 8 drive cage split in half, 2 PCI bus channels.
decided on 2 RAID 1 vols, rest JBOD.
Has OS/Oracle binaries/system on 1 RAID 1 vol

        online redo logs on another RAID 1 vol (also destination for logical exports)

        leaves 6 drives for OFA - without RAID. Has non-paper DBA on staff, doesn't fear performing recovery when one of the non-RAID drives dies.
External LVD tape drive (Ecrix VXA-1 33/66 is my current favorite) Has actually tested recovery strategy, DBA reads this list. 8^)

Strategy 3. RAID on all vols - relying on Ultra 160/m 10,000 RPM drives for performance
configured for maximum write and read rate, concurrency not as much an issue. Dual Fast Ethernet NICs configured for Load balance, fail-over. again, Dell PowerEdge 4400, 10 internal drives, 3 I/O channels - 64 MB of cache per channel
vol drives RAID

0        2            1            OS, Oracle Binaries, System, online redo
1        4            0+1        IDX, TEMP
2        4            0+1        USR, RBS
no hot spares, but has 2 cold spare drives sitting in a box, locked up. no DBA on site - box remotely monitored by 3rd party vendor.

Strategy 4 - discovered external cabinets (2). all channels RAID + hot spared. Moved up to 4 CPU box. Gigabit Ethernet. 3 PCI bus channels, 64 bit, 66 MHz. imagine that you might implement parallel server someday. Design the boxes such that you only have instance specific files in the internal cabinet
6 internal drives: (3 internal I/O channels used - 3 Quad channel RAID controllers)
I/O vol drives RAID

0      0        3            1 + hot spare    OS, Oracle, arch logs1
1      1        3            1 + hot spare    online redo
2      2        2            1                       arch logs 2
3      3        2            1                      System, exports
        4        2            1                      RBS_Small, RBS_Big
                  1                    + hot spare
4       5        5            0+1 + hot spare    Temp1,Temp2
5       6        5            0+1 + hot spare    Indx1, User2
6       7        5            0+1 + hot spare    User1, Indx2

                  28 drives - including 6 hot spares. Yum.

Has n+1 power supplies, spare RAID controller, NIC on site. Still, it doesn't have a dedicated volume/I/O channel for storing a disk copy of backups.
There was a white paper that had that configuration, complete with 4 tape drives Received on Sat Sep 02 2000 - 01:06:41 CDT

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