Computer 101 -- Disk Array

[scott_417]

Take DL380 as an example. It comes with 6 disk drives. Assume I put disk 1 and 2 into Array 1, while disks 3 to 5 into Array 2.

1) Is this Array 1 daisy-chained?

2) From the SCSI point of view, does it take the Array 1 as a "big" disk, while take the Array 2 as another "big" disk, --correct?

3) Under the Linux Operating System, take the Array 1 as example, for Disk 1 in this array, I want to put the OS in one directory, the DBMS in another directory, while the Log file in the third directory. How can I do it ?(go to the Linux prompt to create directory or else?)

(Under Windows OS, though, I'll usually parse the hard drive into many logic drives such C:, D:, and E:. But for Linux, how can I do the equivalent directory parsing? Also, under Windows, when I do the disk parsing, I'll have to specify the capacity for a logic drive such as C: drive (15GB), D: drive (10 GB) etc. NOw under Linux, do I need to specify the capacity for each directory?).


Thanks to help.

Scott

[Ivan Ferreira · Accepted solution]

2) Every array need a logical unit, and every logical unit is a big disk. You can create more than one logical drive in an array. That means that you can create an array with all disks, and create one or more logical drives in that array.

3) Every logical drive in the array will be seen as an idependent disk in linux. For what you want:

I want to put the OS in one directory, the DBMS in another directory, while the Log file in the third directory

You can create three logical drives in the array, the size of the logical drive will be the size of the disk in l inux. Then you will do the usual, partition the logical drive, create the filesystem (format) and mount it (join it to the root filesystem).

Supose that you created 1 logical drive of 100 GB, you can use the whole 100 GB in linux, by creating just 1 partition, creating the filesystem, and mounting it in /oracle for example. When you save data to /oracle, you will be saving data to that logical drive.

Or, you can partition that logical drive by using linux fdisk command to create two partition of desired size, lets say, 50 GB each. Then create the filesystem in the partitions and mount them where you want, let's say /oradata1 and /oradata2.

[Steven Clementi]

Scott:

1. Technically, all of the drives are daisy chanind, but since the backplane handles the connectivity, you can't really "see" it. If you use the duplex option, drives 1 and 2 are on 1 chain and 3, 4, 5 and 6 are on the second chain.


Steven

[Prashant (I am Back)]

Hi,

I think This will explain for cabeling part as pointed in last

Check the attachement

Prashant S.