RAID 5 Not Showing Correct Capacity

[PAnde6]

Hi Guys,

First time RAID setup for me. I setup a RAID 1, and then decided to change to RAID 5. I utilized the data migration setting when I changed from RAID 1 to RAID 5. But I have two problems. The RAID isn't showing the correct capacity and it's slow. I've searched the board, and found lots of other people with speed problems but not capacity. Because I have both problems, I tend to think it's because of my lack of knowledge.

Motherboard: ASUS Strix Z270i (New board so I assume it has the best Intel chipset?)

Processor: Intel i5 7500 @ 3Ghz

RAM: 16Gb DDR4 3200

OS: Windows 10

RAID Disks: 3 x Seagate ST2000LM015 2TB BarraCuda 2.5" SATA3 5400RPM

I believe with 3 x 2TB drives I should have a storage capacity of 4TB but the array shows as only 2TB? and speed is extremely slow. 4Mb/sec write and 20Mb/sec read.

The array is still migrating data. Will storage capacity change when it's finished migrating?

Should I format the drives and start from scratch?. Are the problems I'm having because there was data already on one of the drives?

Peter

[idata · Accepted solution]

Hi Petey: Thank you very much for contacting the Intel® Rapid Storage Technology communities. We will do our best to provide the information you are looking for.

In regard to your first question, yes, the size should be 4TB, and what we need to do is to increase the RAID volume on the Intel® RST application or in disk management. Please check the instructions on the picture below:It is expected for the PC to have a slow performance while the data is migrating, so, before trying anything, we will need to wait for that process to get completed and then the performance should go back to normal. Any further questions, please let me know. Regards,Alberto R

[PAnde6]

Hi Alberto,

When I had the array setup as RAID 1 the capacity was 2TB. I think the RST software automatically kept the capacity at 2TB when I changed to RAID 5.

I got impatient and started from scratch. Formatted the drives individually and created the RAID 5 in RST and PRESTO! RAID 5 with 4TB storage. I did a quick speed test and got 270Mb/s read and 250Mb/s write. The array is just initializing now, and is taking fooooooorever. But apparantly that is normal and I can continue to use the array while it's intializing.

RAID is pretty complex. But Intel's RST has made it a breeze . I partitoned off a portion off my NVMe drive to use as cache, but it doesn't appear in RST?

Thanks for your help

Peter

[idata]

Hi Petey: Thank you very much for letting us know those details. In regard to your inquiry, remember that the acceleration feature will not work when using an NVMe SSD, it works when using a regular SATA SSD.

Any questions, please let me know. Regards,Alberto R

[PAnde6]

Hi Alberto,

I've purchased a 32GB Optane module as a cache drive. I assumed that being NVMe pcie it would have really fast write speeds. I've noticed in the specifications the write speed is only 280Mb/sec?. Should I have purchased an 128GB SSD with 450Mb/sec write speed?. They are the same price.

Regards,

Peter

[idata]

Petey: In regard to your question, if you are using an optane module, even though it s NVMe, you will be able to use it for acceleration, it will work better than a regular SATA SSD. If you are using an NVMe SSD, the acceleration feature will not work with it.

Any questions, please let me know. Regards,Alberto R