AMI BIOS RAID Utility Imposes 1.46TB Partition Size Limit On 6TB SATA HDD Array Drives

A brief word of explanation:

Although I’m using OM Lx 4.3 Ryzen (see specific details below), I am quite sure that the operating system is not part of the problem I am experiencing.

I’m reaching out here to anyone who might have any familiarity or knowledge that might be able to provide any information to help me resolve this issue. Maybe someone on the forum happens to know something that could help.

Hopefully the following inserted text file upload explains the situation in sufficient detail:

AMI BIOS RAID Utility Imposes 1.46TB Size Limit On 6TB SATA HDD Array Drive Partitions.txt (1.9 KB)

Results of the contacts I have made thus far have not resolved the issue.

Researching the question online has provided some slightly related references, but no exact matches to my specific circumstances regarding the problem of the BIOS RAID disk partitions being created undersize:

Either they addressed the same problem but with only a slight percentage of shrinkage due to overhead, or they refer to a 2TB partition limit that seems to be a problem regardless of whether it’s generated by a BIOS RAID utility or simply a storage drive partition issue at the operating system level.

As I have explained in the attached file, the situation I’m encountering is clearly only a problem from the partitions generated by the BIOS RAID utility, and does not occur at the operating system level if I generate the partitions for regular (i.e., non-RAID) storage drive use.

If anyone has any information that would directly address the specific circumstances I’m encountering, I would be very appreciative for any details that could be provided, as I am extremely eager to resolve this issue and complete the setup so the system can be fully operational and placed online.

Thank you very much for your assistance.

never use bios raid option for install linux ,
only use dmraid ( see dmadm ) options

Thanks for your reply, Stephane.

I am curious… why do you say “never use bios raid option for install linux”?
Would you expect that a non-Linux operating system would report the RAID array partition size differently than KDM Partition Manager?

And why do you recommend using dmraid instead?
What do you expect would be different about using dmraid?
(BTW, I’m not familiar with dmraid; I will look into it.)


all Raid bios are proprietary raid , and your are locked with any hardware chipset withe the motherboard , if something fails you cant retrieve your data unless getting same motherboard

that’s why there is no real format Raid in any tools parted / partition manager ,
there is 2 ways : one with mdadm , other is lvm ( logical groups )

see this , for more

another trouble is calamares , they do not support a full straigh install for raid systems ,
you can prepare all disks and format raid , but it will required change
on /etc/fstab , on modules required ( dracut ) , and how get entry UEFI ( you cant have for a group , 2 entry with a logical UUID disks) for boot , in most case boot and efi are not inside the raid partitions

next point is for update , in many case this is done in cold boot ( it means other boot USB or disk , chroot raid partitions , do updates , then reboot )

Ok, thank you.

What I am attempting is to set up the two WD 6TB SATA HDD drives as a RAID 1 array.
I will take a look at theWiki link you sent.

Thanks again.

After considering your reply, I definitely prefer an open source solution. I didn’t know there were any, so thanks for bringing it to my attention.

I understand that the command line solution offers the best option flexibility, I also see others talking about GUI alternatives for convenience, and I feel a certain appeal to that.

Do you have any experience and/or thoughts regarding the alternatives in the attached file?

Linux Software RAID Options.txt (176 Bytes)

Tanks for your help, Stephane. I appreciate whatever input you might have to say about it.