Discovering FakeRAID in the Real World
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@obsolesce said in Discovering FakeRAID in the Real World:
@scottalanmiller said in Discovering FakeRAID in the Real World:
In both of your examples you leave out the most common case - which is that you configure the RAID during the OS install. There is only one step, no multiple steps.
You're right, that's basically the second part here:
@obsolesce said in Discovering FakeRAID in the Real World:
or
1.) Install OS
2.) Configure software RAID
(yes, software RAID here is superior in this case)And yes, this is (well, what you said) is the best way to do it on desktops IMO.
Very few desktops need RAID at all. But when they do, enterprise software RAID is the way to go, IMHO. Safer, better understood, less to go wrong, a vendor to look to if necessary. Windows specifically makes their own software RAID unnecessarily hard. Originally this was to promote hardware RAID sales in the 1990s. It just kind of lingers on from there and sadly caused the FakeRAID market to spring up as a result.
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@obsolesce said in Discovering FakeRAID in the Real World:
@scottalanmiller said in Discovering FakeRAID in the Real World:
Another common way to expose most FakeRAID, try installing VMware ESXi on it. Hardware RAID has to work, FakeRAID would require that VMware have the drivers built in.
I woudln't install VMWare ESXi on my home desktop... then I couldn't use it! So this isn't one of the 99% scenarios we're talking about here.
That's not my point, though. It just makes it really simple to see that the RAID is not on or from the motherboard, because when you look at it with VMware, it's not there at all. You keep the motherboard, but take away the OS, and the RAID vanishes completely.
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@obsolesce said in Discovering FakeRAID in the Real World:
Having it on the BIOS is easy, like in the first example, if you don't use software RAID.
This is the bad wording. It's using the BIOS to edit the config file, nothing more. All of the RAID is software installed on the OS. The BIOS is arguably a handy place to make configuration changes (I think it's horrible because you can't access it on a running system, and it's very hard to assist someone with remotely), but that's all that it is. Like opening Notepad and making a config file change. Its' not notepad doing anything, any tool that could access the file could change it.
It's important, that one time configuration. But it's nothing like providing the RAID. Take away the RAID driver in the OS, and that config file is just an unused, useless text file.
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So @scottalanmiller would you agree that FakeRAID is software RAID that is only configurable through BIOS. So while it is Software at it's heart its such a small, no-name version of software RAID that using it in production is insane. On the level of using FreeNAS.
?
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Dustin asked for a glimpse of FakeRAID vs. Software RAID typical with MD RAID.
This is a little hard, as it's a concept vs. an implementation. But assuming the typical desktop motherboard included FakeRAID approach...
FakeRAID on the Desktop
Configuration is done by the BIOS menu prior to OS install.
Changing configs typically results in data loss.
Data recovery is possibly, but extra tricky.
Configuration is stored on the motherboard, not on the drives (but can be discoverable.)
Features like cache management, block sizes, write through, advanced RAID levels, etc. are generally not available.
Monitoring is often not available.
System is not portable and replacing the motherboard is tricky.
Motherboard failure can result in data loss. Major risk.MD RAID
Configuration is initially done as part of the OS install within the installer.
Changing configs, within reason, can be done without data loss on a running system.
Data recovery is highly likely and simple.
Configuration is stored in the bootloader area of the drivers, and always available.
Loads of caching, management, and tweaking features are available.
Monitoring is included, so you can see the status of the array at any time.
System is portable and does not require any hardware specifics.
Motherboard failure has no risk to data loss. Trivial risk. -
@dustinb3403 said in Discovering FakeRAID in the Real World:
So @scottalanmiller would you agree that FakeRAID is software RAID that is only configurable through BIOS. So while it is Software at it's heart its such a small, no-name version of software RAID that using it in production is insane. On the level of using FreeNAS.
?
FakeRAID is any software RAID attempting to fool the customer that it is hardware RAID. If you configure software RAID through a BIOS menu and it is openly software, not hardware, it would not be FakeRAID. Still pretty silly, but not FakeRAID.
Dell and HPE both make some really silly software RAID devices that require hardware dongles and configure through the BIOS, but are NOT FakeRAID. They are semi-decent software RAID, and often quite superior to Windows Software RAID. They are not free, but do all the things that @Obsolesce wants like early BIOS style menus, but do so in an enterprise way.
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So you would agree that FakeRAID wouldn't be called FakeRAID if it wasn't attempting to masquerade as if it was hardware based, but instead just stated that it was actually Software RAID with a silly configuration menu.
Since it is still software. Correct?
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@dustinb3403 said in Discovering FakeRAID in the Real World:
So you would agree that FakeRAID wouldn't be called FakeRAID if it wasn't attempting to masquerade as if it was hardware based, but instead just stated that it was actually Software RAID with a silly configuration menu.
Since it is still software. Correct?
Correct. What makes it "fake" is that it is "faking" that it is hardware. Not that it is faking being RAID. It's real RAID, just not real hardware.
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Another good resource.
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@scottalanmiller said in Discovering FakeRAID in the Real World:
@pete-s said in Discovering FakeRAID in the Real World:
@dustinb3403 No, Broadcom 3008 has it's own integrated cpu, on board memory etc. It's just not enough performance for it to do all kinds of raid. It's the same controller as Dell H330 and a bunch of others make cards with it as well.
From the specs:
The SAS 3008 offered with the Avago Integrated RAID (IR) feature is a
low cost, high performance RAID solution designed for blade, entry and
mid-range servers that require redundancy and high availability but where
a full featured RAID implementation is cost prohibitive or not desired. The
Avago advanced Integrated RAID options include Integrated Mirroring
(IM), which is RAID 1, Integrated Mirroring Enhanced (IME), known as RAID
1E, Integrated Striping (IS), which is RAID 0, and Integrated Mirroring and
Striping (IMS) which is RAID 10. By simplifying the RAID configuration
options, Integrated RAID is easy to install and configure and meets the
needs of most internal RAID requirements.https://mangolassi.it/topic/6375/examining-the-dell-perc-h310-controller/
The H3xx series is hardware. Terribly slow hardware, but hardware.
The H330 is a 3008 based product but it has a different firmware package, and some cut down internals so it has a much lower queue depth, and a bastardized mega-raid capability (no write cache). There is memory on the card, but it's for the queues.
The HBA330 isn't slow it @#%@% flies but it's pass through only. It is the full queue'd (exposes the raw possible queue based on the memory which is crazy high), and has no firmware option for a RAID firmware.
The H310 was a LSI2008 based ASIC package which had its queue crippled to something pathetic like 25.
Dell runs their own trunk for HBA firmware's rather than just grabbing various checkpoints on the tree is my understanding, so beyond these customizations, you will sometimes see different behavior. Sometimes they will selectively ship a fix, and avoid a feature they found problematic or didn't want (Tri-Mode RAID wasn't supported on the newest PERC's at first).
The controller industry is crazy opaque.
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@scottalanmiller said in Discovering FakeRAID in the Real World:
Dell and HPE both make some really silly software RAID devices that require hardware dongles and configure through the BIOS, but are NOT FakeRAID.
You talking about the S series, or the Intel CPU ROC functions for NVMe drives (which have a dongle for certain features, or the ability to use non-Intel drives). I thought the OEM's were shunning VROC.
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@storageninja said in Discovering FakeRAID in the Real World:
The controller industry is crazy opaque.
This is really the only thing worth considering when looking for a controller. .
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At home, I'll use LVM to build the RAID when using Linux, or the built-in RAID on my mobo with Windows. I don't want to spend extra money on enterprise RAID for at home. 99% of what I have at home is stateless, so reloads are easy. Worst case is I have to reinstall 70GB of games, but that's backed up so it's easy if I hit a scenario I cannot recover a RAIDed disk, or whatever.
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@scottalanmiller What about RAID 1 on the motherboard? Yeah it's "fake", but it's still effectively mirroring the drives. I use that on my home pc and it hasn't failed me.
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@dave247 said in Discovering FakeRAID in the Real World:
@scottalanmiller What about RAID 1 on the motherboard? Yeah it's "fake", but it's still effectively mirroring the drives. I use that on my home pc and it hasn't failed me.
Thats what we use .
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@dave247 said in Discovering FakeRAID in the Real World:
@scottalanmiller What about RAID 1 on the motherboard? Yeah it's "fake", but it's still effectively mirroring the drives. I use that on my home pc and it hasn't failed me.
Depends on the implementation. Normally the question is not about whether it is better than nothing, but how is it better than the Windows OS' included RAID 1?
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@wrcombs said in Discovering FakeRAID in the Real World:
@dave247 said in Discovering FakeRAID in the Real World:
@scottalanmiller What about RAID 1 on the motherboard? Yeah it's "fake", but it's still effectively mirroring the drives. I use that on my home pc and it hasn't failed me.
Thats what we use .
Is it? I thought you just determined that you didn't have FakeRAID, but had to use Windows RAID instead (which is the recommended choice anyway.)
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@obsolesce said in Discovering FakeRAID in the Real World:
At home, I'll use LVM to build the RAID when using Linux, or the built-in RAID on my mobo with Windows. I don't want to spend extra money on enterprise RAID for at home.
That IS enterprise in the Linux case. Windows Software RAID is free, too, maybe not enterprise, but not horrible to the point of not being better than nothing.
Enterprise RAID is almost always free.
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@storageninja said in Discovering FakeRAID in the Real World:
@scottalanmiller said in Discovering FakeRAID in the Real World:
Dell and HPE both make some really silly software RAID devices that require hardware dongles and configure through the BIOS, but are NOT FakeRAID.
You talking about the S series, or the Intel CPU ROC functions for NVMe drives (which have a dongle for certain features, or the ability to use non-Intel drives). I thought the OEM's were shunning VROC.
That's newer, and there is some interesting stuff there.
But I'm talking about the older SAS controller options (maybe it is S series?) that are basically just SAS controllers with drivers to install, but they are open about it and don't hide anything. Basically just a trivial step up from Windows Software RAID, but with support for Hyper-V, VMware ESXi, and most everything else, plus really simple management utilities.
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@scottalanmiller there isn’t a software based raid option on ESXi unless you pass it to a VM or use vSAN. The cheapest raid controllers supported are the BOSS modules M.2 mirroring things.
