CentOS 7 Configure MD OBR10 before installation

[DustinB3403]

So here's the breakdown as I've never done this process specifically I have 4 SSD's in a system that I want configured to operate in OBR10.

How can I configure this pre-installation so that all 4 disks can be used?

[DustinB3403]

Eh. . . you know maybe I'm an idiot but it looks like this might actually be included in the installation options. . . .

Eh. . .

[black3dynamite]

Just have to change the device type to RAID.

[DustinB3403]

@black3dynamite yeah I've never actually done that and than realized it was there lol . . .

[momurda]

Or you can use Ctrl Alt F2 to get a # prompt and do it through cli

[DustinB3403]

And now the next issue. . .

Of course I have 3 matching SSD's of 500 GB each, and the 4th is of course 1TB. And I don't want to wast the space. lol

[travisdh1]

@dustinb3403 said in CentOS 7 Configure MD OBR10 before installation:

And now the next issue. . .

Of course I have 3 matching SSD's of 500 GB each, and the 4th is of course 1TB. And I don't want to wast the space. lol

You'll have to create a 500GB partition on the 1TB one then. Mark that partition as a RAID device. Partition and mount the rest of the 1TB as you wish.

[JaredBusch]

Or better yet, just use the three 500GB in a RAID5. I mean we are talking SSD here. You still get the 1TB space that you would get from the 4x 500GB in RAID 10

[DustinB3403]

@jaredbusch but I don't get the IOPS, which for the operation that this system is being setup for is most critical component.

[DustinB3403]

@jaredbusch usually I would agree.

[DustinB3403]

@travisdh1 said in CentOS 7 Configure MD OBR10 before installation:

@dustinb3403 said in CentOS 7 Configure MD OBR10 before installation:

And now the next issue. . .

Of course I have 3 matching SSD's of 500 GB each, and the 4th is of course 1TB. And I don't want to wast the space. lol

You'll have to create a 500GB partition on the 1TB one then. Mark that partition as a RAID device. Partition and mount the rest of the 1TB as you wish.

Crisis averted. I found another 500GB!

[JaredBusch]

@dustinb3403 said in CentOS 7 Configure MD OBR10 before installation:

@jaredbusch but I don't get the IOPS, which for the operation that this system is being setup for is most critical component.

I cannot imagine a general workload that would saturate this.

So what kind of workload do you have?

[DustinB3403]

@jaredbusch said in CentOS 7 Configure MD OBR10 before installation:

@dustinb3403 said in CentOS 7 Configure MD OBR10 before installation:

@jaredbusch but I don't get the IOPS, which for the operation that this system is being setup for is most critical component.

I cannot imagine a general workload that would saturate this.

So what kind of workload do you have?

4K video and file rendering with massive files (1TB plus). Only running the 1 file at a time to offload from our team.

[JaredBusch]

@dustinb3403 said in CentOS 7 Configure MD OBR10 before installation:

@jaredbusch said in CentOS 7 Configure MD OBR10 before installation:

@dustinb3403 said in CentOS 7 Configure MD OBR10 before installation:

@jaredbusch but I don't get the IOPS, which for the operation that this system is being setup for is most critical component.

I cannot imagine a general workload that would saturate this.

So what kind of workload do you have?

4K video and file rendering with massive files (1TB plus). Only running the 1 file at a time to offload from our team.

Yup, definitely not a general workload.

I would love to see th IOPS numbers while in use.

[Obsolesce]

@jaredbusch said in CentOS 7 Configure MD OBR10 before installation:

@dustinb3403 said in CentOS 7 Configure MD OBR10 before installation:

@jaredbusch said in CentOS 7 Configure MD OBR10 before installation:

@dustinb3403 said in CentOS 7 Configure MD OBR10 before installation:

@jaredbusch but I don't get the IOPS, which for the operation that this system is being setup for is most critical component.

I cannot imagine a general workload that would saturate this.

So what kind of workload do you have?

4K video and file rendering with massive files (1TB plus). Only running the 1 file at a time to offload from our team.

Yup, definitely not a general workload.

I would love to see th IOPS numbers while in use.

I just got this on a VM on a busy hyper-v host, copying a 7GB file:

Not impressive, but I wish i still had the screenshots from a long time ago on the host itself. Lots of IOPS.

[DustinB3403]

@obsolesce are you using top there?

[scottalanmiller]

@dustinb3403 said in CentOS 7 Configure MD OBR10 before installation:

@obsolesce are you using top there?

Looks like iostat

[Obsolesce]

@scottalanmiller said in CentOS 7 Configure MD OBR10 before installation:

@dustinb3403 said in CentOS 7 Configure MD OBR10 before installation:

@obsolesce are you using top there?

Looks like iostat

Yes, iostat

[Emad R]

@dustinb3403

Hi,

You cant but the /boot as raid

However the / or root part can be placed as raid, I did this and I will show you how to do this, but please don't do it.

Here where it gets bad.

You wish to update the system and kernel and all this can affect the RAID/ now the config for the raid is done in the kernel and stored in boot part, so you always updating this and your always keeping the disks busy, even on network packet level. Everything happens will happen on the /

What you want to do is look into purchasing a small reliable drive
Like 64 GB or 128 GB NVMe SSD and using that as your /
or If that is too fancy or expensive, get USB thumb drive and pair it with samsung SD card and install the root part

Then create RAID 10 on the 4 other drives, cause even if the /root fails it wont matter . pop another one and it will auto detect the raid , with cockpit it is very easy to detect the RAID and activate it and mount it