1.5.1.3Raw Devices
Raw devices are disk partitions or logical volumes that have not been formatted with a file system.When you use raw devices for database file storage, Oracle writes data directly to the partition or volume, bypassing the operating system file system layer. for this reason, you can sometimes achieve performance gains by using raw devices. however, because raw devices can be difficult to create and administer, and because the performance gains over modern file systems are minimal, oracle recommends that you choose Automatic Storage Management or file system storage in preference to raw devices.
When installing oracle using the bare device storage option in Linux, you can configure it as follows:
In this example,/dev/sda/dev/sdb/dev/sdc/dev/sdd/dev/sde/dev/sdf is available in linux.
/Dev/sda for operating system software installation
/Dev/sdb for ocr disk
/Dev/sdc for votingdisk
/Dev/sdd/dev/sde/dev/sdf is used for shared disk storage. Each disk is partitioned according to the specified size (500 mb ).
Disk Partitions are as follows:
[Root @ node1 ~] # Fdisk-l
Disk/dev/sda: 16.1 GB, 16106127360 bytes
255 heads, 63 sectors/track, 1958 cylinders
Units = cylinders of 16065*512 = 8225280 bytes
Device Boot Start End Blocks Id System
/Dev/sda1*1 64 514048 + 83 Linux
/Dev/sda2 833 1958 9044595 83 Linux
/Dev/sda3 65 701 5116702 + 83 Linux
/Dev/sda4 702 832 1052257 + 5 Extended
/Dev/sda5 702 832 1052226 82 Linux swap/Solaris
Partition table entries are not in disk order
Disk/dev/sdb: 536 MB, 536870912 bytes
64 heads, 32 sectors/track, 512 cylinders
Units = cylinders of 2048*512 = 1048576 bytes
Device Boot Start End Blocks Id System
/Dev/sdb1 1 512 524272 83 Linux
Disk/dev/sdc: 536 MB, 536870912 bytes
64 heads, 32 sectors/track, 512 cylinders
Units = cylinders of 2048*512 = 1048576 bytes
Device Boot Start End Blocks Id System
/Dev/sdc1 1 512 524272 83 Linux
Disk/dev/sdd: 3221 MB, 3221225472 bytes
255 heads, 63 sectors/track, 391 cylinders
Units = cylinders of 16065*512 = 8225280 bytes
Device Boot Start End Blocks Id System
/Dev/sdd1 1 391 3140676 5 Extended
/Dev/sdd5 1 62 497952 83 Linux
/Dev/sdd6 63 124 497983 + 83 Linux
/Dev/sdd7 125 186 497983 + 83 Linux
/Dev/sdd8 187 248 497983 + 83 Linux
/Dev/sdd9 249 310 497983 + 83 Linux
/Dev/sdd10 311 391 650601 83 Linux
Disk/dev/sde: 3221 Mbit/s, 3221225472 bytes
255 heads, 63 sectors/track, 391 cylinders
Units = cylinders of 16065*512 = 8225280 bytes
Device Boot Start End Blocks Id System
/Dev/sde1 1 391 3140676 5 Extended
/Dev/sde5 1 74 594342 83 Linux
/Dev/sde6 75 148 594373 + 83 Linux
/Dev/sde7 149 222 594373 + 83 Linux
/Dev/sde8 223 296 594373 + 83 Linux
/Dev/sde9 297 391 763056 83 Linux
Disk/dev/sdf: 8589 MB, 8589934592 bytes
255 heads, 63 sectors/track, 1044 cylinders
Units = cylinders of 16065*512 = 8225280 bytes
Device Boot Start End Blocks Id System
/Dev/sdf1 1 1044 8385898 + 5 Extended
/Dev/sdf5 1 62 497952 83 Linux
/Dev/sdf6 63 124 497983 + 83 Linux
/Dev/sdf7 125 186 497983 + 83 Linux
/Dev/sdf8 187 248 497983 + 83 Linux
/Dev/sdf9 249 310 497983 + 83 Linux
/Dev/sdf10 311 372 497983 + 83 Linux
/Dev/sdf11 373 434 497983 + 83 Linux
/Dev/sdf12 435 496 497983 + 83 Linux
/Dev/sdf13 497 558 497983 + 83 Linux
/Dev/sdf14 559 620 497983 + 83 Linux
/Dev/sdf15 621 682 497983 + 83 Linux
Disk/dev/sdg: 8589 MB, 8589934592 bytes
255 heads, 63 sectors/track, 1044 cylinders
Units = cylinders of 16065*512 = 8225280 bytes
