[SunHELP] Instasll DiskSuite 4.1

[Frank-Christian Kruegel]

On Mon, 14 May 2001 17:44:40 +0900, you wrote:

>Hi Frank-Christian Kruegel-san ,
>
>Thank you for your advice.
>
>>RAID5 in software is slow. If speed matters, better use hardware RAID =
if money
>>permits or RAID10 (striping and mirroring, gives you less capacity).
>
>If you know, couldn't you please tell me the following.
>
>Is write/read performance of RAID5 in software lower than using hard =
disk singly ?
>I need the performance of Soft-RAID as same as single hard disk.
>Purpose of using DiskSuite is to construct the large volume disk by =
aggregation=20
>of low price disks.
>
>Has operaton of Software RAID using DiskSuite lain a burden on CPU ?
>Platform(EP250) is equipped with single CPU only.

As you may know, RAID5 adds reliability to a drive array by adding an =
additional
drive and spreading XOR checksums across all disks (in contrast to RAID4,=
 which
uses a dedicated parative drive). These XOR operations add extra load to =
the
main CPU. Hardware RAID controllers have extra XOR hardware for this.

So the answer is "yes" for both questions.

If you only want a lange volume and are willing to take the risk that one=
 drive
may fail, then RAID0 is what you are looking for.

RAID 0: Striping
RAID 1: Mirroring
RAID 4: Failsafe with dedicated parity drive
RAID 5: Failsafe with parity spread across all drives
RAID 10: RAID 0 and RAID 1 together (striping of mirrors disks)

You might consider external RAID controllers, which have several SCSI =
and/or
=46CAL interfaces to connect to the host and to the drives. I've worked =
with CMD
TITAN controllers (http://www.cmd.com/), and the price/performance ratio =
was
much better than with a SUN A5100/A5200.


Mit freundlichen Gr=FC=DFen

Dipl.-Ing. Frank-Christian Kr=FCgel
IstDa Kommunikationssysteme