Re: Problem with sata2 and raid1.

Am Samstag, den 12.04.2008, 15:42 +0200 schrieb Erik P. Olsen:
I have installed two sata 2 drives - each 250 GB - which I want to use in a
raid1 configuration. My mobo - MSI K8T Neo2 - does not support those sata
drives, so I have therefore installed a RocketRaid 1720 PCI-card to get the
necessary hardware support.

As to my knowledge the 1720 is not a real hardware raid controller but a
fake raid, i.e. the controllers firmware provides some software to do
some limited raid management, but all the real work is done by your
computers hardware via kernel drivers.

I have therefore decided to switch to the software available with Fedora and
would like to know if the data already located on the disks is accessible to the
Fedora driver or if I have to reformat the drives and install all the enchilada
from the beginning?

There is a chance that both use a standard format to manage the raid
disks, so your data may be readable. If you have a full backup you
should just try.

Luckily I have back-up of everything and can recreate all
data it just takes more time. Another even more important question is will
Fedora drive the disks through the RocketRaid controller or should I get
different hardware and if so which?

In both cases you drive the disks through the 1720. If you use dmraid,
the controllers bios is used for some operations. I you use md, you
disable the controllers bias and just use the SATA connectors and drive
access logik.

In terms of performance: it's equal. read is the same as if you had a
single disk, write doubles the time needed to write to the disks
(because write operations will be performened twice, one operation for
each disk).

In terms of administration: md does not use propriarity firmware
drivers. In case of a failure or other problem it is easier to check and
handle the disks.

As a general advice: you have to use dmraid/controllers firmware if you
need to share the drives with windows OS, otherwise you should use md.

IT you need better performance you should buy a real hardware raid.
Highpoint RocketRaid 3120 is a cheap one with solid linux support, or
areca ARC1200 (a little bit more expensive). Areca has an excellent
linux driver and installation support, but can not operate with some WDC
Raptor disks (10.000 Upm).


Peter


--
fedora-list mailing list
fedora-list@xxxxxxxxxx
To unsubscribe: https://www.redhat.com/mailman/listinfo/fedora-list

Relevant Pages

  • Re: Accessing disks via their serial numbers.
    ... with multiple controllers using the same driver there is ... you have to replace broken hardware. ... someone has two fxp adapter configured on system. ... they have disks as children. ...
    (freebsd-arch)
  • Re: SATA on Linux vs. WinXP WAS Help me to get rid of windows forever
    ... > It depends on the hardware. ... > over software raid. ... The compaq controllers also have a commandline ... > In the last 10 years I have had to replace a number of drives on various ...
    (Fedora)
  • Re: Problem with sata2 and raid1.
    ... so I have therefore installed a RocketRaid 1720 PCI-card to get the necessary hardware support. ... would like to know if the data already located on the disks is accessible to the Fedora driver or if I have to reformat the drives and install all the enchilada from the beginning? ... the controllers bios is used for some operations. ...
    (Fedora)
  • Re: RAID5 ... N/Work with 300 GB SATA drives ... Likely Hardware Problem
    ... I did check the Disks using PowerMax (the failing drives are Maxtor SATA ... > using just in case it's a hardware problem. ...
    (microsoft.public.windows.server.sbs)
  • Re: 1581 Drive Clicking
    ... both HD and DD disks, ... would not format HD disks to 720K. ... PCs and XTs had DD controllers and drives. ... Early ATs had HD controllers and 5.25 drives, ...
    (comp.sys.cbm)