An INTEL Server motherboard model SE7501BR2 with an onboard Adaptec AIC7901 controller (with HostRAID) is not being recognized by CENTOS 4. The AIC79xx driver loads correctly, however it does not "see" the fact that I used the HostRAID onboard software to create a RAID 1 set.
I went to the INTEL site and only found a driver for RHEL 3.0 and I was unable to find a driver on the adaptec site.
The CENTOS4 installer gives me the option to create partitions, raids, etc. This is not what we want since creating a RAID by software it's supposed to be more slow that doing it hardware based right?
Does the CENTOS4 support the AIC7901 with HostRAID or not?
Thanks for your comments and suggestions.
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------------------------------------------- Erick Perez Linux User 376588 http://counter.li.org/ (Get counted!!!) Panama, Republic of Panama
On Sat, 2005-10-29 at 12:45 -0500, Erick Perez wrote:
An INTEL Server motherboard model SE7501BR2 with an onboard Adaptec AIC7901 controller (with HostRAID) is not being recognized by CENTOS 4. The AIC79xx driver loads correctly, however it does not "see" the fact that I used the HostRAID onboard software to create a RAID 1 set.
I went to the INTEL site and only found a driver for RHEL 3.0 and I was unable to find a driver on the adaptec site.
The CENTOS4 installer gives me the option to create partitions, raids, etc. This is not what we want since creating a RAID by software it's supposed to be more slow that doing it hardware based right?
I haven't bench marked it myself, but many other have stated software raid 1 performs very well. The added benefit of not having to worry about another driver is always a plus. You should run some tests against your requirements for your self, you may be surprised.
Does the CENTOS4 support the AIC7901 with HostRAID or not?
Thanks for your comments and suggestions.
--
Erick Perez
Ted
Erick Perez wrote:
An INTEL Server motherboard model SE7501BR2 with an onboard Adaptec AIC7901 controller (with HostRAID) is not being recognized by CENTOS 4. The AIC79xx driver loads correctly, however it does not "see" the fact that I used the HostRAID onboard software to create a RAID 1 set.
I went to the INTEL site and only found a driver for RHEL 3.0 and I was unable to find a driver on the adaptec site.
The CENTOS4 installer gives me the option to create partitions, raids, etc. This is not what we want since creating a RAID by software it's supposed to be more slow that doing it hardware based right?
Does the CENTOS4 support the AIC7901 with HostRAID or not?
In Adaptec speak HostRAID is software RAID. What you have is not hardware RAID controller. The card is really just a standard SCSI controller with fake RAID BIOS. Create software RAID devices under CentOS (and you'll get exactly the same thing as if configuring them in BIOS and using Adaptec device driver).
But having a "fake" bios doing raid1 isnt' more stable/better than to emulate raid1 in software?
however, thinking of benchmarks, the machine in question is a dual xeon with 512mb ram doing web,smtp,pop3 and a small mysql for 50 users. I think raid 1 with the linux driver will be more than excellent.
However the main question remains, Why the adaptec 79xx driver does not "see" that I created a raid1 in the bios? why keeps showing me two "drives" instead of one?
Cause that will mean that the linux 79xx is not "fully" compatible (ok, it is 99.999999% compatible) with the AIC-7901 Adaptec 320 with HostRAID (fake BIOS or not).
Comments welcomed,
On 10/29/05, Aleksandar Milivojevic alex@milivojevic.org wrote:
Erick Perez wrote:
An INTEL Server motherboard model SE7501BR2 with an onboard Adaptec AIC7901 controller (with HostRAID) is not being recognized by CENTOS 4. The AIC79xx driver loads correctly, however it does not "see" the fact that I used the HostRAID onboard software to create a RAID 1 set.
I went to the INTEL site and only found a driver for RHEL 3.0 and I was unable to find a driver on the adaptec site.
The CENTOS4 installer gives me the option to create partitions, raids, etc. This is not what we want since creating a RAID by software it's supposed to be more slow that doing it hardware based right?
Does the CENTOS4 support the AIC7901 with HostRAID or not?
In Adaptec speak HostRAID is software RAID. What you have is not hardware RAID controller. The card is really just a standard SCSI controller with fake RAID BIOS. Create software RAID devices under CentOS (and you'll get exactly the same thing as if configuring them in BIOS and using Adaptec device driver). _______________________________________________ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
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------------------------------------------- Erick Perez Linux User 376588 http://counter.li.org/ (Get counted!!!) Panama, Republic of Panama
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On Sat, Oct 29, 2005 at 06:07:35PM -0500, Erick Perez wrote:
But having a "fake" bios doing raid1 isnt' more stable/better than to emulate raid1 in software?
Actually, no. First, it is not really an emulation, but a full directly implementation. The second reason is that the raid implemented by the controler is also software based, and Linux raid1 implementation is supperior.
However the main question remains, Why the adaptec 79xx driver does not "see" that I created a raid1 in the bios? why keeps showing me two "drives" instead of one?
Cause that will mean that the linux 79xx is not "fully" compatible (ok, it is 99.999999% compatible) with the AIC-7901 Adaptec 320 with HostRAID (fake BIOS or not).
Again, no. It is not that Linux is not complatible with HostRAID. It is most of a fact that HostRAID does not exist by itself.
Think of it this way. When you implement Raid1 using Linux on those drives, and then boot the same machine on Windows, Windows won't recognize the md device either. It is exactly the same thing. HostRAID is as much of a software raid as Linux softraid.
Of course this is a simplification, but it is what HostRAID really boils down to in the end.
[]s
- -- Rodrigo Barbosa rodrigob@suespammers.org "Quid quid Latine dictum sit, altum viditur" "Be excellent to each other ..." - Bill & Ted (Wyld Stallyns)
On Sun, 2005-10-30 at 13:50 -0200, Rodrigo Barbosa wrote:
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On Sat, Oct 29, 2005 at 06:07:35PM -0500, Erick Perez wrote:
But having a "fake" bios doing raid1 isnt' more stable/better than to emulate raid1 in software?
Actually, no. First, it is not really an emulation, but a full directly implementation. The second reason is that the raid implemented by the controler is also software based, and Linux raid1 implementation is supperior.
However the main question remains, Why the adaptec 79xx driver does not "see" that I created a raid1 in the bios? why keeps showing me two "drives" instead of one?
Cause that will mean that the linux 79xx is not "fully" compatible (ok, it is 99.999999% compatible) with the AIC-7901 Adaptec 320 with HostRAID (fake BIOS or not).
Again, no. It is not that Linux is not complatible with HostRAID. It is most of a fact that HostRAID does not exist by itself.
Think of it this way. When you implement Raid1 using Linux on those drives, and then boot the same machine on Windows, Windows won't recognize the md device either. It is exactly the same thing. HostRAID is as much of a software raid as Linux softraid.
Of course this is a simplification, but it is what HostRAID really boils down to in the end.
---- if not a marketing tactic attempting to imbue extra value.
Craig
Can you belive that? And INTEL is bundling such controllers on high end server boards.
Well, thanks to all. I will surely use the Linux Raid1 setup and run-away from the HostRAID-based cards.
Note to ADAPTEC: Shame on you. ;)
Thanks, Erick.
if not a marketing tactic attempting to imbue extra value.
Craig
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------------------------------------------- Erick Perez Linux User 376588 http://counter.li.org/ (Get counted!!!) Panama, Republic of Panama
Craig White wrote:
if not a marketing tactic attempting to imbue extra value.
Well. It is just an market anomaly created by the Microsoft's decision to disable software RAID feature in non-server versions of Windows. For whatever reason, Microsoft decided that desktop users don't need software RAID. Probably using the same logic that coined the famous "640Kb is enough for everybody" phrase.
After engineering was done with its job (which was actually quite logical thing to do), marketing simply went one step further by not telling people what really they are spending their money on: standard disk controller with software RAID device driver. Given the almost non-existant laws for consumer protection in western world, almost anything can go.
Erick Perez wrote:
But having a "fake" bios doing raid1 isnt' more stable/better than to emulate raid1 in software?
Actaually no. Linux software RAID is way more tested and stable then any propriatary fake RAID driver. Since fake RAID drivers are really just implementation of software RAID, you do not gain absolutetly anything by using them.
Simply set the BIOS to JBOD mode (do not define any RAID devices in it), and do standard Linux software RAID thing. Usually, it will be faster than using propriatary device driver.
There are only two reasons for using those fake RAIDs.
First is if you are building Windows 2000/XP home, workstation or professional box. Microsoft ships software reaid drivers only for server version of Windows. So those fake RAID drivers are about the only way to get software RAID in home, workstation and professional version of Windows. Actually, if you check difference in price between normal (non-RAID) controller and its equivalent fake-RAID version, usually it is less than difference in price between Windows Pro and Windows Server license (otherwise, there would be no economical sense for buying the fake-RAID card).
Second is if you are installing more than one OS on the box (for example Windows and Linux) and you want both operating systems to share some or all of the RAID devices.
However the main question remains, Why the adaptec 79xx driver does not "see" that I created a raid1 in the bios? why keeps showing me two "drives" instead of one?
Cause that will mean that the linux 79xx is not "fully" compatible (ok, it is 99.999999% compatible) with the AIC-7901 Adaptec 320 with HostRAID (fake BIOS or not).
None of the fake RAID device drivers will ever become part of mainstream Linux kernel. The approach Linux takes to support them is to use device mapper. Basically, during boot, Linux would read fake RAID info from BIOS, and than configure device mapper appropriately. This is a generic approach that will work with all fake RAID controllers, using stable and well tested device drivers that are already part of the kernel. If you are interested in doing things this way (configure RAID in BIOS and than use device mapper), type dmraid in Google. Dmraid already has support for many fake RAID cards.
This should answer your question why 79xx device driver (the one which is part of standard kernel) does not see those fake RAID devices you created. It simply sees tha card for what it really is. Standard SCSI controller. What you bought from Adaptec is standard SCSI controller and software RAID driver for Windows. Linux comes standard with it (unlike non-server versions of Windows), so you don't need that additional software under it. If you really want to use fake-RAID devices in BIOS, use dmraid to configure device mapper during boot.
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Aleksandar Milivojevic -
Craig White -
Erick Perez -
Rodrigo Barbosa -
Ted Kaczmarek