OT 2nd posting pci ata card ??

Antony Gelberg antony at wayforth.co.uk
Sun Apr 2 09:26:44 UTC 2006

Matthew Kuiken wrote:
> Dave S wrote:
>> On Saturday 01 April 2006 20:21, Patrick Siglin wrote:
>>> On Sat, 1 Apr 2006 20:02:47 +0100, Dave S wrote
>>>>> Is you dvdrw plugged into the raid card? If so do you have an onboard
>>>>> ide interface you can move it to? I basically do the same thing but
>>>>> have my dvdrom and dvdrw on the onboard and my two ide drives on the
>>>>> adaptic raid controller and have no problems.
>>>>> -- 
>>>>> poison at list.memphistw.org (http://www.memphistw.org)
>>>> I had not though of changing the drives around like this :)
>>>> OK question time ...
>>>> (1) I have software raid, are you software raid or does the card
>>>> handle it ?
>>>> (2) Which card do you have, does it have PATA connections, my HDDs
>>>> are PATA
>>>> (3) what you say makes sense :) (first time RAID user)
>>>> Dave
>>>> -- 
>>>> ubuntu-users mailing list
>>>> ubuntu-users at lists.ubuntu.com
>>>> https://lists.ubuntu.com/mailman/listinfo/ubuntu-users
>>> I have a hardware raid. My card is an ata raid controller not PATA. 
>>> How are
>>> your drives setup? Do you have your hd's on one controller and the 
>>> dvdrw on
>>> another? I would always suggest hardware raid over software.
>>> -- 
>>> poison at list.memphistw.org (http://www.memphistw.org)
>> At present I have hda  HDD, hdc HDD, hdb DVDRW all connected to the 
>> motherboard controllers.
>> hda & hdc are assigned as software raid. when I use hdb boy does the 
>> system suck :) so I was looking at moving hdb to PCI ATA controller.
>> looks like I might have got it the wrong way round. Bought a 
>> controller (v. cheap) with parallel ATA connections for my DVDRW and 
>> found it will not work as a PATA only a SATA with the kernel drivers 
>> available.
> I would highly recommend changing to a hardware RAID IDE card.  The 
> downside to this is that I am not certain that you will not need to 
> re-install in the process of moving the drives from software RAID on the 
> MB to the hardware RAID on an add-in card.  It may work, but I would not 
> hold my breath.
> The biggest benefit of hardware RAID will be in performance.  You will 
> get the speed increase of being able to read from mirrored disks, the 
> reliability of having the two drive system, and the write speeds won't 
> have the overhead of software needing to perform two separate writes, 
> the hardware will take care of it.  In all, if you are adding a card, it 
> is wise to move the RAID functionality into hardware.

Do you have any evidence to back this up?  Most hardware RAID cards are 
just normal IDE cards with RAID drivers.  Unless you spend obscene 
money.  The overhead you speak of is negligible on every system I've 
used software RAID on.

> One side effect from this, if it is not already, the swap partition will 
> also be RAIDed.  Since the RAID is in hardware, the drives will have to 
> be true mirrors.  It is a good idea to have the swap in RAID for system 
> reliability anyway, but as was discussed in a previous thread, some 
> people do not mirror swap because of the write performance issues.  Once 
> the write is in hardware, this is no longer as big an issue.
> I am running on a laptop, so I don't have any suggestions for the exact 
> card.  I hope to do a desktop install soon, but that could still be a 
> ways off.  I have a really old computer (Pentium MMX) that I'll be doing 
> the install on, so I am watching this thread for ideas as to what 
> hardware I will want to upgrade to also.

Software RAID is better for most users as it's not dependent on any 
specific hardware, and is very configurable.

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