TS-877XU-RP RAID option

[jarstor]

Hi.

I am wondering the acquisition of a NAS QNAP TS-877XU-RP, with:
- AMD Ryzen 5 2600 6core@3.4GHz
- 16GB DDR4
- 8 WD Red Pro WD4003FFBX 4 TB
- QNAP QM2-2P-244A (drives M.2 NVMe) with 2 Samsung 970 EVO Plus MZ-V7S1T0BW 1TB internal M.2 2280 PCI Express 3.0 x4

This QNAP is destined to have file shares available to some internal teams. It will be added to a windows domain so permissions are easily defined for each team or individual user if needed.
Can you help me decide on the RAID I should use (10, 6 ,5)? I'm tempted for RAID 10. The shares will be used mostly to have simultaneous office users to upload smartphone/camera photos (business is e-commerce). At the moment total size of documents is 4TB. Uploads can sometimes be up to 10GB (thousands of files). And maybe to work on some word or excel files remotely (shared documents). Network is 1Gbps (hope to upgrade to 10Gbps in the near future). Users want fast file transfers to QNAP, of course.

I would also like to use the virtualization station to have 2 or 3 linux VMs, if this wont overcharge the QNAP.

Hope to hear some of you with more experience
Thanks.

[dolbyman]

RAID6 .. faster and more reliable than RAID10 (as tested in these md software raid environments)

But with 1GbE it doesn't matter anyways .. even a single disks would be much faster than that

VM images should go on the SSD storage

[QNAPDanielFL]

"QM2-2P-244A"
This is a lower-performance QM2 card that won't take full advantage of the M.2 NVMe speed.
244 means PCIe gen2X4 for the card. So that bottlenecks the SSDs somewhat.

QM2-4P-384 is a much better card to hold 2 or 4 M.2 NVMe drives.

You could make an SSD pool with NVMe for your VM images. If you get 4 M.2 drives you can use 2 M.2 for VM images and 2 M.2 for cache for your HDD pool. 12 HDDs RAID 6 throughput is good already, but SSD cache can help with many smaller files where IOPS tends to be the bigger concern.

[jarstor]

Thanks a lot for your input.
Maybe I'll opt for RAID6 and change to a QM2-4P-384 card.

One more question, what about RAID rebuilding times if a disk dies? I've read that many times the rebuilding is very slow and other disks tend to die on the process also. Is this true? Can you still use the QNAP when rebuilding, even if at lower speeds?
RAID10 in this case would be better? Or you still prefer RAID6?

Regards.

[QNAPDanielFL]

You can use the NAS while it is rebuilding but the performance is less during the rebuild. The rebuild can take about 1-2 days depending on the size of the drive. RAID6 takes longer to rebuild than RAID 10. But if only one drive fails and you start a rebuild, the chances of 2 drives failing during the rebuild should be low. So I still think RAID6 is a good option.

[jarstor]

How about configuring the SSD cache? Should configure in Raid1 and "read-write" mode?

[dolbyman]

As said put a VM volume on the SSD's they can't have mixed usage so no cache or tier possible

[jarstor]

Yes, you're right dolbyman. But if I decide not to use virtualization station (VMs), what mode should I use?

[dolbyman]

both cache and tier can help, do nothing, or make it worse

I would try it out (both are removable again)