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:
@dustinb3403 said in Discovering FakeRAID in the Real World:
@pete-s are you certain it isn't the same FakeRAID we're discussing here?
I'd be interested in seeing what models specifically include this.
LSI only makes hardware RAID, AFAIK. But I know for certain that SuperMicro makes real server boards with entry level hardware RAID on them. Some others do, too. But in the desktop space, which was the basis for the originally discussion from the other thread, I'm not sure if they offer that as well, or not.
All fakeraid I've seen (on motherboards) was never LSI. It's usually part of the chipset like AMD or Intel.
AMD used to do hardware RAID, believe it or not. That's the HP dx5150. It was an AMD chipset doing it. It existed before the OS installed, true hardware beginning to end.
Intel is the largest and most outspoken FakeRAID vendor. They are the big maker of add-on FakeRAID cards.
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@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.
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@wrcombs said in Discovering FakeRAID in the Real World:
@dustinb3403 said in Discovering FakeRAID in the Real World:
@pete-s that board appears to have fakeRAID
Intel® C622 controller for 10 SATA3 (6 Gbps) ports; RAID 0,1,5,10 Broadcom® 3008 SW controller for 8 SAS3 (12Gbs) ports; RAID 0,1,10With this we can assume that raid 0,1,5,10 are all FakeRAID? this that correct?
RAID levels are not related to software, or hardware RAID.
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@wrcombs said in Discovering FakeRAID in the Real World:
@dustinb3403 said in Discovering FakeRAID in the Real World:
@obsolesce said in Discovering FakeRAID in the Real World:
When I buy a motherboard that comes with RAID, vs one that does not come with RAID, the difference is significant if your end goal is to have a RAID5 for example. So, lets assume that you want to build a home computer that has a RAID5:
Motherboard that comes with RAID:
- Configure RAID in bios
You can't configure raid in BIOS, period.
You can setup a configuration file, but the OS installation is setting up the array way after the installation has started.
wouldn't CTLR+R (or in my case it was F for Fast track) allow you to configure RAID? and make sure Bios are set to boot with the RAID ?
No, you do not have FakeRAID either. Nor can you do this to configure any business class RAID, you should never, ever do this regardless of if you have the option.
FakeRAID is always bad (maybe it's okay for some cases for like home entertainment boxes, but even then, Windows does it better natively.) There really is no good case for FakeRAID. It might save a few seconds over Windows RAID in setup, but when do you want to take on the risk for a few seconds saved up front?
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@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.
Having it on the BIOS is easy, like in the first example, if you don't use software RAID.
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@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.
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@dustinb3403 said in Discovering FakeRAID in the Real World:
@obsolesce said in Discovering FakeRAID in the Real World:
@wrcombs said in Discovering FakeRAID in the Real World:
@dustinb3403 said in Discovering FakeRAID in the Real World:
@obsolesce said in Discovering FakeRAID in the Real World:
When I buy a motherboard that comes with RAID, vs one that does not come with RAID, the difference is significant if your end goal is to have a RAID5 for example. So, lets assume that you want to build a home computer that has a RAID5:
Motherboard that comes with RAID:
- Configure RAID in bios
You can't configure raid in BIOS, period.
You can setup a configuration file, but the OS installation is setting up the array way after the installation has started.
wouldn't CTLR+R (or in my case it was F for Fast track) allow you to configure RAID? and make sure Bios are set to boot with the RAID ?
@Obsolesce is that what you are talking about? I'm just trying to learn, I knew nothing about RAID at the beginning of the day...
Yeah, even if you have a dedicated hardware RAID card... such as the Dell PERC H730p, you have the ability to enter the RAID card's BIOS by hitting CTRL+R.
That is because you'd have dedicated hardware intercepting the boot process so you can configure the array. It's not hardware raid because something is stopping the boot process to throw up a menu that you can jump into.
It's not interrupting the boot process, it's just a normal BIOS menu. It might be accessed through a second key combination, but it's just something you can optionally do during the boot process. Interrupting makes it sound like it stalls it or something. It's typically at the same time as other options like the standard BIOS Menu or the Boot Order.
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@dustinb3403 said in Discovering FakeRAID in the Real World:
@wrcombs said in Discovering FakeRAID in the Real World:
@dustinb3403 said in Discovering FakeRAID in the Real World:
@obsolesce said in Discovering FakeRAID in the Real World:
When I buy a motherboard that comes with RAID, vs one that does not come with RAID, the difference is significant if your end goal is to have a RAID5 for example. So, lets assume that you want to build a home computer that has a RAID5:
Motherboard that comes with RAID:
- Configure RAID in bios
You can't configure raid in BIOS, period.
You can setup a configuration file, but the OS installation is setting up the array way after the installation has started.
wouldn't CTLR+R (or in my case it was F for Fast track) allow you to configure RAID? and make sure Bios are set to boot with the RAID ?
@Obsolesce is that what you are talking about? I'm just trying to learn, I knew nothing about RAID at the beginning of the day...
That "option" is what is fakeRAID.
Take that motherboard and throw it out, and grab those drives. Nothing else in the world would know that the drives are of an array. (especially in a disaster recovery scenario)
They would. They just might not load it. It's just Software RAID. Nothing in FakeRAID suggests that it won't work on other hardware. It might not, but that's not an artefact of it being FakeRAID.
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@obsolesce said in Discovering FakeRAID in the Real World:
Holy shit, you're just as bad as Scott putting words in my mouth.
I can't be, I always quote where you said the thing I'm repeating.
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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.
