RAID Controller Shenanigans or Misinterpretation?

[Brio]

Has anybody ever experienced this? I'm setting up a RAID for myself (namely because I wanted to, not because it's the best method) and decided on RAID 5 due to the capacity of 3 drives and the redundancy of 1. During setup I entered my RAID card's BIOS and started manually configuring the thing. Then when I was ready to hit yes I noticed a slight issue.

 

 

According to Linus in his As Fast as Possible series on RAID arrays; For RAID 5 I should have the capacity of however many drives I have minus one for parity. The math being (Capacity of 1 drive) x (# of drives in the array - 1 drive (for parity). If I'm understanding this correctly then, I should be looking at somewhere in the neighborhood of 12TB out of these four 4TB drives. What I find myself seeing is not even close. 5TB? Am I missing something?

 

Gets even weirder with RAID 10:

 

RAID 10 as I understand it (RAID 1+0) should at least be giving me the capacity of half of the drives in the array? So why then is the capacity not even the size of a single bare drive? Can anybody help me diagnose this? It seems really odd. ;w ;

 

EDIT: The RAID card is a VANTEC 6-Port SATA II 150 PCI Host Card Model UGT-ST310R and I'm using four 4TB Seagate Barracuda Drives I have available to me.

 

Edited January 19, 2018 by Brio
Added information on RAID card model.

[Anghammarad]

I miss the screen where you chose the raid mode, add the drives etc... 

 

The usual controllers I worked with automatically count the final size... well you could change it but why?

 

Choosing the drives, set raid level for the selected disks and everything should usually be fine. If the controller supports the raid modes.

[Brio]

1 hour ago, Anghammarad said:

I miss the screen where you chose the raid mode, add the drives etc... 

 

The usual controllers I worked with automatically count the final size... well you could change it but why?

 

Choosing the drives, set raid level for the selected disks and everything should usually be fine. If the controller supports the raid modes.

 

These are all the options there are. Logically it makes no sense that the capacity would be so small. Trying to increase the size it goes past the initial threshold down to 2GB and hitting the down arrow to go back it jumps back up to 5034 GB meaning that's the max size its saying it can be. The card supports RAID 1, 0, 5, 10 and everything is as it should be in the booklet instructions here: https://www.vantecusa.com/CKEdit/images/files/ugt-st310r_manual.pdf

 

So either I fundamentally lack understanding of how a RAID works or there's some shenanigans with the math going on here.

[Anghammarad]

@BrioExpand the Chunk size to the max and check again

[Brio]

4 minutes ago, Anghammarad said:

@BrioExpand the Chunk size to the max and check again

You'd think that would do something...yet the chunk size has no effect on the final raid size in this case. In a RAID 5 array here it stays firmly at a max size of 5034GB and in RAID 10 it stays at 3356GB. The only thing that seems to change the size is the RAID type and it merely goes down further on the other options. Changing the number of discs its using also doesn't seem to affect the size beyond the effect of reducing the already tiny size.

[Anghammarad]

7 minutes ago, Brio said:

You'd think that would do something...yet the chunk size has no effect on the final raid size in this case. In a RAID 5 array here it stays firmly at a max size of 5034GB and in RAID 10 it stays at 3356GB. The only thing that seems to change the size is the RAID type and it merely goes down further on the other options. Changing the number of discs its using also doesn't seem to affect the size beyond the effect of reducing the already tiny size.

I went for that due to own experience with the LSI Raid Controllers in the IBM Servers we have at work. 

 

When it is too small, the raid volume can't expand to the full size, depending on the total space.

 

So when you run auto mode setup and chose the 4 drives... does it change a thing? 

 

Even so, when going through with all the settings and saving the config, after reboot the volume shown on startup is smaller than it should be, exact the size shown in the config menu? 

 

Edit incoming

 

Just went for a search for the controller you linked the manual from... It says on the Vantec website the controller only supports drives up to 2 tb each. perhaps that is the culprit here, the controller not being able to address the drives correctly.

[Brio]

11 minutes ago, Anghammarad said:

I went for that due to own experience with the LSI Raid Controllers in the IBM Servers we have at work. 

 

When it is too small, the raid volume can't expand to the full size, depending on the total space.

 

So when you run auto mode setup and chose the 4 drives... does it change a thing? 

 

Even so, when going through with all the settings and saving the config, after reboot the volume shown on startup is smaller than it should be, exact the size shown in the config menu? 

 

 

 

Auto mode unfortunately does nothing but determine the chunk size automatically at 64K and select all available drives for the array.

 

I am hesitant to save the config beyond this point because I don't want to have to format the metadata off the drives to try and change it. As the drives are brand new I don't want to format them over and over in an attempt to get them to work. Changing the amount of drives plugged in from 4 to 3 merely reduces the RAID 5 config down to RAID 10's size. Booting into Windows the drives don't even show up in Disc Management. All I can think of is the card may not be rated for such a "large" RAID size.

[Brio]

40 minutes ago, Anghammarad said:

I went for that due to own experience with the LSI Raid Controllers in the IBM Servers we have at work. 

 

When it is too small, the raid volume can't expand to the full size, depending on the total space.

 

So when you run auto mode setup and chose the 4 drives... does it change a thing? 

 

Even so, when going through with all the settings and saving the config, after reboot the volume shown on startup is smaller than it should be, exact the size shown in the config menu? 

 

 

 

Upon reading some reviews on Newegg it appears that this card cannot support a drive larger than 2TB. Which probably is the issue I'm facing. Not that, that information is shared on the manufacturer's page for the product or in the listing....I do appreciate the attention you've given thus far though. ;w ;

 

Only options available to me it seems are to contact the support department at Vantec or return the card to Microcenter and reassess my available avenues.

[Anghammarad]

3 minutes ago, Brio said:

Auto mode unfortunately does nothing but determine the chunk size automatically at 64K and select all available drives for the array.

 

I am hesitant to save the config beyond this point because I don't want to have to format the metadata off the drives to try and change it. As the drives are brand new I don't want to format them over and over in an attempt to get them to work. Changing the amount of drives plugged in from 4 to 3 merely reduces the RAID 5 config down to RAID 10's size. Booting into Windows the drives don't even show up in Disc Management. All I can think of is the card may not be rated for such a "large" RAID size.

That's where my train of thoughts goes as well... 

 

And it isn't even supported for anything above Vista, getting this from the manufacturers page.