LSI9211-8i question & NAS configurations

Mgrobins

New Member
Nov 28, 2019
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Good evening Networking gurus :D

I'm after advice before the Cyber Monday sales disappear and the lovely savings on HDD's!

Currently have 2 NAS devices at home and making decision on new drives to add -

1. Synology 1812+ 8 bay (3TB x6 RAID5 + 2TBx3 JBOD) -> backs up my main NAS weekly. 1GBe link

2. Xpenology Home Brew NAS: 6x 4TB RAID6 on LSI 9211-8i HBA; -10GBase-T link to my work PC only

-Looking to expand to 8x 4TB on HBA (and in future have separate physical & logical volume on MB SATA ports)
I use 10GBe link to access NAS like DAS or SAN (sorry for butchering nomenclature :rolleyes:). all other gear accesses it at 1GBe including backup NAS (DS1812).


I need some help Please :)

1. PCIe 2.0 (x8?) LSI 9211-8i - correct specs?
Does each drive channel (SAS channel?) have enough bandwidth to fully utilise a SATA 3 HDD, and will the

PCIe 2.0 : 3,200MB/s max @ 500MB/s per lane (correct?) should be ample.

2. DS1812+ :
I consider buying 3x 4TB and have mixed drives in a SHR2 arrangement that I will grow with 4TB+ drives as I need.

I've read commentary from flawed "studies" that SHR is slow compared to RAID... never used it myself.

I don't use encryption so my Atom CPU should be ok for SHR? ... any hands on experience with SHR2 and its speed VS RAID6?

NOTE:
DS1812 only has 1GBe so unless the SHR array is totally bogged down I'm assuming it will exceed NIC throughput? (no teaming since I only use it for backup from my main NAS, and it cant be fitted with a 10GBe NIC. I know rebuild, scrub times etc are super important too... but they can also happen slow time in background given its core usage pattern.


Appreciative of any input folks may have :).