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4452
May 6th, 2020 02:00
Software RAID on R720 with SAS disks
Hello,
I'm trying to find answers to my questions. Do a software raid configuration is possible on R720 with SAS disks ?
Moreover I don't understand the purpose of these connectors.(cf picture);R720 motherboard
theflash1932
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16.3K Posts
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May 7th, 2020 09:00
"Even using h310 in passthrough mode for mdam on linux, if raid controler failed, i have to put the same card with same firmware to not loose everything"
I don't believe passthrough mode writes any metadata to the drives, so in theory, you would not need an H310 controller to read the drives on another controller (although you may need to adjust the boot device/drivers on the image "offline" to be able to boot it from another controller), and the controller just would need to be the same or newer than the old controller (although even older firmware *may* not be a problem).
I don't use passthrough - I always use the H7xx controllers - so I can't say for certain.
"im afraid too by h310 performances"
Yeah, they aren't great controllers, but they do support passthrough. If you want performance, get the H710 controller.
"I use raid controler on DCs and i'm not relaxed but it was impossible without on dell r710"
Sure it was possible. You could have 1) had "no" controller and managed the disks individually as AHCI devices, or 2) used an H200 controller, which also supports passthrough. You just couldn't use SAS disks in AHCI (again, not sure if that has changed on the R720).
theflash1932
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16.3K Posts
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May 6th, 2020 06:00
Can't see your picture.
What kind of "software RAID" are you looking for? A Dell PERC "software" controller? or Windows/Linux managed RAID?
The answer to both is yes. You can use the onboard S110 to mirror drives, but it is garbage, and I would highly recommend you mirror your disks in the OS instead, if you must use software RAID. The S110 is a WINDOWS-ONLY controller. If you are concerned at all about performance, reliability, or the ability to troubleshoot/fix issues with your RAID, I'd highly recommend you use the H710 controller, which is an add-in card for hardware RAID.
whappen
16 Posts
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May 6th, 2020 07:00
@theflash1932Im looking for software RAID on MDAM (linux).
How to connect sas disks to motherboard ?
You can't see my pictures, weird.
For hardware RAID what do you think about H710 mini 512MB NV RAM ? It's less expensive than h710P but i didn't see sas connector on the h710 mini.
theflash1932
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16.3K Posts
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May 6th, 2020 14:00
Of course (and I meant to lead with this on my previous post), there is the possibility that SAS drives are NOT supported at all on the chipset - possibly especially if RAID is disabled. My GUESS? You will need a card like the H310 to connect SAS drives, used in passthrough mode so that Linux can see the physical drive and manage the mirror.
theflash1932
9 Legend
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16.3K Posts
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May 6th, 2020 14:00
I can see it now.
Looks like that slot is indeed min-SAS (although not a traditional one, may be some sort of expander slot).
The bottom one says it is the mini-SAS for software RAID (meaning the S110) ... you *may* need to connect the drives to this slot and disable RAID in the BIOS for onboard/embedded devices, which should then pass the drives through as AHCI devices. I cannot say for sure on any of this ... just an educated guess based on experience with many different systems.
I'm guessing the larger mini-SAS is wired to the integrated storage slot to pass the drives through to hardware RAID controllers in the dedicated storage slot.
whappen
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May 7th, 2020 00:00
@theflash1932
What a beautiful reply.Thank you
My biggest fear is raid card's failures. Even using h310 in passthrough mode for mdam on linux, if raid controler failed, i have to put the same card with same firmware to not loose everything. You know what i mean.
I hate hardware controler for their inflexibility.
But im afraid too by h310 performances.
Each one have their avantages & disavantages and it's really difficult for me. I use raid controler on DCs and i'm not relaxed but it was impossible without on dell r710.
whappen
16 Posts
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May 11th, 2020 05:00
@theflash1932
Well well thank you. If i had known i wouldn't have sas disks.
By curiosity, can i put a h700 on r720. It will work ?
I have plenty