Re: what kind of raid is this?

[Bob Marčan]

On Wed, 05 Mar 2025 22:05:13 -0800
"ToddAndMargo via users"  wrote:
> On 3/5/25 9:05 PM, Jeffrey Walton wrote:
> > On Wed, Mar 5, 2025 at 9:12 PM ToddAndMargo via users
> >  wrote:
> > > On 3/5/25 5:45 PM, Bob Marčan via users wrote:
> > > > > /dev/md126:
> > > > >            Container : /dev/md/imsm0, member 0
> > > > >           Raid Level : raid1
> > > >                             ^^^  
> > >
> > > Not following you.
> >
> > He answered your question. You have RAID1. It is also called Disk Mirroring.
> >
> > Jeff
>
> Hi Jeff,
>
> The question was what type of raid, not what level.
>  From my original post:
>   Raid Level : raid1
>
> Is this RSTe?  Software raid handled by the OS?
> Or something else?
>
> -T

The information you sent, at least to me, does not disclose whether it is SW or Fake Raid. Try to connect this disk to a Linux machine and look there what can be seen there. I would do that myself.

what kind of raid is this?

[Roger Heflin]

It is the fakeraid driver that runs on top of standard md/dm devices.
RST is Intels fakeraid setup.

I am not sure if it will automatically come up (if installed on a
machine without a fakeraid bios and/or not defined in the fakeraid
bios).  There is likely a manual way to force configured it to come up
on another machine.   You would want to check the dm-raid list
archives.

I like to avoid the fakeraids just because they are a bit more trouble
and aren't as well tested/supporting with updates.

On Thu, Mar 6, 2025 at 5:22 AM Bob Marčan via users
 wrote:
> On Wed, 05 Mar 2025 22:05:13 -0800
> "ToddAndMargo via users"  wrote:
> > On 3/5/25 9:05 PM, Jeffrey Walton wrote:
> > > On Wed, Mar 5, 2025 at 9:12 PM ToddAndMargo via users
> > >  wrote:
> > > > On 3/5/25 5:45 PM, Bob Marčan via users wrote:
> > > > > > /dev/md126:
> > > > > >            Container : /dev/md/imsm0, member 0
> > > > > >           Raid Level : raid1
> > > > >                             ^^^
> > > >
> > > > Not following you.
> > >
> > > He answered your question. You have RAID1. It is also called Disk Mirroring.
> > >
> > > Jeff
> >
> > Hi Jeff,
> >
> > The question was what type of raid, not what level.
> >  From my original post:
> >   Raid Level : raid1
> >
> > Is this RSTe?  Software raid handled by the OS?
> > Or something else?
> >
> > -T
>
> The information you sent, at least to me, does not disclose whether it is SW or Fake Raid. Try to connect this disk to a Linux machine and look there what can be seen there. I would do that myself.
>
> --
> _______________________________________________
> users mailing list -- [e-mail]
> To unsubscribe send an email to [e-mail]
> Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/
> List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines
> List Archives: https://lists.fedoraproject.org/archives/list/[e-mail]
> Do not reply to spam, report it: https://pagure.io/fedora-infrastructure/new_issue

what kind of raid is this?

[Barry]

> On 6 Mar 2025, at 11:22, Bob Marčan via users  wrote:
>
> does not disclose whether it is SW or Fake Raid.

Whst is fake raid? I had assume that term just means software raid in the bios.

Barry

what kind of raid is this?

[Bob Marčan]

On Thu, 06 Mar 2025 14:08:26 +0000
"Barry"  wrote:
> > On 6 Mar 2025, at 11:22, Bob Marčan via users  wrote:
> >
> > does not disclose whether it is SW or Fake Raid.
>
> Whst is fake raid? I had assume that term just means software raid in the bios.
>
> Barry

https://www.diskinternals.com/raid-recovery/fakeraid/

what kind of raid is this?

[Barry Scott]

> On 6 Mar 2025, at 14:54, Bob Marčan  wrote:
>
> On Thu, 06 Mar 2025 14:08:26 +0000
> "Barry"  wrote:
> > > On 6 Mar 2025, at 11:22, Bob Marčan via users  wrote:
> > >
> > > does not disclose whether it is SW or Fake Raid.
> >
> > Whst is fake raid? I had assume that term just means software raid in the bios.
> >
> > Barry
>
> https://www.diskinternals.com/raid-recovery/fakeraid/

Rather short of details on that site.

But reading between the lines Fakeraid is software raid and usually Intel RST.

Barry

what kind of raid is this?

[Roger Heflin]

Fakeraid is the original name for this when manufacturers came up with
it.   Originally everyone were directly competing with the hardware
raid, and the manufacturers of these raid cards did not go out of
their way to tell anyone it was 99.9% software.

There were fakeraid raid5/raid6 controllers that did not clarify that
it was 99.9% software, hence the term being "fakeraid", as every other
raid controllers prior to this were 100% hardware.   And typically the
fake raid needing their own heavy lifting driver were not integrated
into the kernel and needed a 3rd party driver, with all of the risks
of a 3rd party driver (lack of updates and support).

On Thu, Mar 6, 2025 at 8:09 AM Barry  wrote:
> > On 6 Mar 2025, at 11:22, Bob Marčan via users  wrote:
> >
> > does not disclose whether it is SW or Fake Raid.
>
> Whst is fake raid? I had assume that term just means software raid in the bios.
> Barry
>
> users mailing list -- [e-mail]
> To unsubscribe send an email to [e-mail]
> Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/
> List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines
> List Archives: https://lists.fedoraproject.org/archives/list/[e-mail]
> Do not reply to spam, report it: https://pagure.io/fedora-infrastructure/new_issue

what kind of raid is this?

[Roger Heflin]

highpoint had multi-port raid5 fakeraid cards in the 2006 timeframe
and was very careful about not disclosing it was 99.9% software and
required an extra driver.

There were others that had these cards also, they were troublesome and
even intel's has issues at times.

On Thu, Mar 6, 2025 at 9:04 AM Barry Scott  wrote:
> > On 6 Mar 2025, at 14:54, Bob Marčan  wrote:
> >
> > On Thu, 06 Mar 2025 14:08:26 +0000
> > "Barry"  wrote:
> > > > On 6 Mar 2025, at 11:22, Bob Marčan via users  wrote:
> > > >
> > > > does not disclose whether it is SW or Fake Raid.
> > >
> > > Whst is fake raid? I had assume that term just means software raid in the bios.
> > >
> > > Barry
> >
> > https://www.diskinternals.com/raid-recovery/fakeraid/
>
> Rather short of details on that site.
>
> But reading between the lines Fakeraid is software raid and usually Intel RST.
>
> Barry
>
> --
> _______________________________________________
> users mailing list -- [e-mail]
> To unsubscribe send an email to [e-mail]
> Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/
> List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines
> List Archives: https://lists.fedoraproject.org/archives/list/[e-mail]
> Do not reply to spam, report it: https://pagure.io/fedora-infrastructure/new_issue

what kind of raid is this?

[Stephen Morris]

On 7/3/25 01:54, Bob Marčan via users wrote:
> On Thu, 06 Mar 2025 14:08:26 +0000
> "Barry"  wrote:
> > > On 6 Mar 2025, at 11:22, Bob Marčan via users  wrote:
> > >
> > > does not disclose whether it is SW or Fake Raid.
> >
> > Whst is fake raid? I had assume that term just means software raid in the bios.
> >
> > Barry
>
> https://www.diskinternals.com/raid-recovery/fakeraid/

On the previous motherboard I had (and possibly the current one, I 
haven't investigated the functions it provides) I was sold the 
motherboard on the grounds that it provided Raid10 which I wanted. In 
order for the Raid10 to be used, and install Windows to it, I needed to 
supply bios provided drivers at Windows install time so that Windows 
could actually see the Raid devices to install to, and from what the 
article is saying that was an indication that it was fake raid which 
should allow Windows and Linux to be installed to the same devices and 
be interchangeable in a dual boot situation that I was doing, that was 
not the case with the implementation. While with the supplied drivers 
Windows was able to see the devices and install to them, Fedora 
Workstation would not install on the devices on the grounds that it 
could not see them, and the bios did not supply Linux drivers. At the 
time I was getting this issue I found documentation on the net that said 
Fedora Workstation could not install to Raid only Fedora Server could.

regards,

Steve

what kind of raid is this?

[Tim]

On Thu, 2025-03-06 at 14:08 +0000, Barry wrote:
> Whst is fake raid? I had assume that term just means software raid in
> the bios.

RAID done by the motherboard, either completely on its own, or
requiring specialist drivers.  And is depending heavily on the
motherboard for its existence, and quite likely to use the drives in a
manner incompatible with anything else (such as having to replace the
motherboard, or having to pull out a drive to read it on something
else).

The same can probably be said for drives plugged into a daughterboard
into the motherboard.  And I dare say for external boxes full of hard
drives that appear like mass storage to the computer.

I'd say the most foolproof scheme is a bunch of drives plugged into
multiple drive ports on the motherboard, and having the OS create a
RAID out of them.

While some will argue about the potential speed differences between the
various schemes, and others will argue it's not really that
significant, the original poster's purpose for the system would suggest
reliability is the main criteria.  They're not doing high-speed data
processing (such as rendering 3-D raytracing or high def video
editing).

what kind of raid is this?

[John Mellor]

On 2025-03-06 9:29 p.m., Tim via users wrote:
> On Thu, 2025-03-06 at 14:08 +0000, Barry wrote:
> > Whst is fake raid? I had assume that term just means software raid in
> > the bios.
>
> RAID done by the motherboard, either completely on its own, or
> requiring specialist drivers.  And is depending heavily on the
> motherboard for its existence, and quite likely to use the drives in a
> manner incompatible with anything else (such as having to replace the
> motherboard, or having to pull out a drive to read it on something
> else).
>
> The same can probably be said for drives plugged into a daughterboard
> into the motherboard.  And I dare say for external boxes full of hard
> drives that appear like mass storage to the computer.
>
> I'd say the most foolproof scheme is a bunch of drives plugged into
> multiple drive ports on the motherboard, and having the OS create a
> RAID out of them.
>
> While some will argue about the potential speed differences between the
> various schemes, and others will argue it's not really that
> significant, the original poster's purpose for the system would suggest
> reliability is the main criteria.  They're not doing high-speed data
> processing (such as rendering 3-D raytracing or high def video
> editing).

Hardware RAID cards are expensive, have ludicrously expensive batteries, 
and have no concept of empty sectors or filesystems and so have to 
methodically replicate every sector blindly.  This is a problem, 
especially when doing a recovery.  Software RAID using JBOD and a 
journaling filesystem that can do RAID (ZFS, BTRFS, a couple of others) 
is usually somewhat faster in read and normally hundreds of times faster 
than hardware RAID in recovery.  The only edge case where hardware RAID 
might even compete is when the array is near or at 100% full and there 
are no sectors where a software RAID can do something more intelligent.