Trunas on Older Dell servers

[0m3n]

Hi all,

i got an old dell t720 server that ive used as a storage server running truenas, in the past i raided the drives raid 1 C raid 5 storages and had a drive failure, when attempting to swap out the failed disk it caused massive complications, so i lost all my data and went back to the drawing board, i upgraded it to SSD 1tb disks running i think raidz.

my question is, if a disk fails and i need to replace it, i have to go into the raid controller swap it out there and then its seen as bogus in truenas.... in short, is there a way to set this up that i dont have to loose everything should a disk fail ?

not all of us are loaded with cash, so we take the best we can find and try make the most out of it with the help / mercy of devs like you. is there a proceedure to swap failed drives out that are within a BIOS managed config or is that something you gents will consider building into this in the future ? cause i think a feature where a new disk could be added to a raid, and then just merged into the ZFS pool and rebuilt would be extreamly useful to guys like me running old ass servers.

Kindest regards
S

 

[Arwen]

TrueNAS Core & SCALE use ZFS for RAID. It appears you are using a hardware RAID controller card which is in-compatible with ZFS. This describes the issue;

What's all the noise about HBAs, and why can't I use a RAID controller?

1) An HBA is a Host Bus Adapter. This is a controller that allows SAS and SATA devices to be attached to, and communicate directly with, a server. RAID controllers typically aggregate several disks into a Virtual Disk abstraction of some sort...

www.truenas.com

Also, if you can supply the output of the following commands, we can get a better picture of your layout;
zpool list zpool status

I do understand the desire to use available hardware to get something working. But, ZFS is simply not reliable on consumer hardware RAID controller cards. Now if your system board has enough regular SATA ports, that is an option for ZFS. In which case, please post your entire hardware configuration.

 

[0m3n]

Hi Arwen,

thank for a prompt reply. it wouldnt let me copy paste, so please refer to the attached. this is on a dell T420 server running a perc710 Raid card, when assessing it, it doesnt not seem to support HBA mode, last time a mechanical drive failed, i was able to swap it out and update it in the raid, but then truenas wasnt reflecting the raid update.

the drives are currently all individually raided as raid0 so each drive on the system is seen as single disks and not apart of a hardware raided pool per say, but should a drive fail and i swap it out and update the raid controller the truenas system doesnt or didnt back then reflect it to rebuild the ZVOL, keep in mind this issue happen back with TN ver 12U so i dont know if any changes have been made since then till ver 13.

perhaps a feature that allows truenas to detect drives and add to the current pool as well as remove drives would be a very nice feature to have as well as work around this whole raid issue

Kindest regards
S

 

[NugentS]

Do not use a RAID controller. Running it as a bunch of RAID0 is still using it as a RAID controller.
You will lose data
I don't believe (and others may correct me) that the 710 can be flashed to IT mode. I believe you need to replace it - however before you do - make sure you back up all your data as your disks may not be readable by a proper HBA

 

[jgreco]

it doesnt not seem to support HBA mode

You need an HBA with IT firmware loaded. There is no such thing as an "HBA mode"; it's a fiction to sell more expensive high end RAID hardware. See the article that you were referred to. You either need to replace the PERC with a PERC HBA like the H310 flashed to IT mode, or you can also crossflash the H710 to IT mode. Both ways you end up with an HBA.

the drives are currently all individually raided as raid0 so each drive on the system is seen as single disks and not apart of a hardware raided pool

It is not the "hardware raided pool" that's a problem. It's that there's any RAID in there at all.

i was able to swap it out and update it in the raid, but then truenas wasnt reflecting the raid update.

It's this. Your RAID controller is designed to keep presenting the same set of volumes to the host; it is based on a mentality that assumes that there is redundancy, but there is no redundancy when you have your RAID0 individual devices. The RAID controller is designed to do something different than what ZFS needs, which is direct access to the raw disks. An HBA is fundamentally different in that it does not create virtual volumes.

perhaps a feature that allows truenas to detect drives and add to the current pool as well as remove drives would be a very nice feature to have

TrueNAS has all of that, naturally. But you have to use the correct firmware. You need to flash the PERC H710 to make it into an HBA with IT firmware.

Introduction - Fohdeesha Docs

fohdeesha.com

as well as work around this whole raid issue

The workaround to trying to tow a full size camper with a VW Bug is to replace the VW Bug with a truck, not to find a "work around for the whole VW Bug issue". ZFS needs access to your disks. Hiding them behind a PERC RAID controller is not going to work and is unlikely ever to work. This is not the fault of ZFS or TrueNAS. It's because you need to understand that the job requires a truck, not a VW Bug.

 

[NugentS]

And I stand corrected - apparently you can flash a 710. I would still back up your data before doing so, just in case

 

[0m3n]

NugentS,

forgive my ignorance, so you saying basically i can A either flash the current raid controller and this will be better, or B, replacet eh raid controller with something else ?

can you please assist me with this, what do i need to either flash the perk710 or if you got a link to something i can buy to replace it i will do this ?

Kindest regards
S

 

[0m3n]

AWESOME,

thanks jgreco, if i flash this perk card, will it still function as it does now just with the added features ? or will it just out right turn into something other then what it is now and no longer be able to raid in the future ? ( just tryting to make sure i understand exactly what it is im doing before doing it and possibly cant be undone ) PS sorry the forum only refreshed after posting the previous post

Kindest regards
S

 

[0m3n]

Nuf SAID !!!

thanks guys, you have all been extremely informative, wow this is great, so i can use this and just return to dell stuff if needed down the line, thanks this has answered all my questions.

Kindest regards
S

 

[jgreco]

thanks @jgreco, if i flash this perk card, will it still function as it does now just with the added features ?

No. An HBA is just a device that attaches hard disks "directly" to a host without any drama; it lets processes on the host CPU send commands to the HDD's CPU like "read LBA 12642492". It does use the HBA's onboard CPU as a proxy but there is no repackaging done by the HBA.

A RAID controller, by comparison, uses its CPU to construct virtual disk devices out of a bunch of physical disk devices. When the host CPU sends a command, the RAID CPU intercepts that and issues various commands out to the HDD CPU's involved, reading blocks, computing parity, etc. This is why your "RAID0" disks present themselves as virtual disk devices to the host even though you might be THINKING that this configuration is similar to direct disk access.

Changing a RAID controller to an HBA is essentially a lobotomization. The LSI cards happen to use similar (but more powerful) CPU's in their RAID cards, so if you can get IT firmware to run on the RAID card, then it becomes an HBA. However, LSI only designed this capability into low end RAID cards such as the LSI 9240-8i. Some clever people have nevertheless figured out ways to forcibly load IT firmware onto budget OEM RAID cards such as the Dell PERC H200 or H310, which they're not really supposed to be able to do, and the link I provided above is for someone who did this for the higher end PERC H710.

This is probably a one-way transformation, but I'm not sure that matters. With the deprecation of ESXi 6.7, the market has been flooded by older 6Gbps SAS server gear that is not supported by ESXi 7. A PERC H710 on the used market is about $35-$60.

My recommendation is nevertheless to purchase a pre-crossflashed IT-mode PERC H310, because it is a bit of work to crossflash these cards if you are not comfortable with the arcane toolsets used to do this work.

Either way, you need a card flashed with the IT firmware, version 20.00.06.00.

 

[0m3n]

ok,

so i went and took a look, i ordered this, it cost a bit more then the H310, so i imagine its the better controller, plus the guy said its for freenas ( old truenas ) any thought on it ?

LSI 6Gbps SAS HBA 9200-8i IT Mode ZFS FreeNAS unRAID + 2*SFF-8087 SATA | eBay

Find many great new & used options and get the best deals for LSI 6Gbps SAS HBA 9200-8i IT Mode ZFS FreeNAS unRAID + 2*SFF-8087 SATA at the best online prices at eBay! Free shipping for many products!

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Kindest
S

 

[jgreco]

Likely to be fine.