Hi,
Just in short, my observation dealing with the same dilemma… 6
commodity SATA SSDs and:
1. RAIDZ2 on SATA controller, forced 4k sectors (ashift 12) -> speed at max
~750MB/s
2. RAID6 on Sun SAS6 LSI, default volume setup by controller BIOS, 32kB stripe
(I think), write cache ON (if battery OK), simple zpool -> speed at max. ~1GB/s
3. RAIDZ2 on 6 volumes on Sun SAS6, each volume RAID0 with one disk, 32kB
stripe, write cache ON -> speed at max. ~2.3GB/s
All 3 cases on the same X4170M2 with SmartOS and simple zpool scrub and
watching zpool status reported speed - fresh install with some VMs. No extra
science.
Reliability winner is No.1. Even if your server is half burnt, you have quite
good change to read your data, in worst case with 6 SATA->USB caddies and 6
port USB hub.
Speed winner is No.3, but you have to live with understanding, that if your
controller is gone, so almost for sure your data are gone too. This would be no
issue in cloud business… there one physical server have almost no meaning, when
you properly spread services.
Write cache ON if backup battery is healthy, such setting usually would be
there. Disk cache OFF. As far as I remember HP controllers can be in full
details setup just from some boot CD - cache spliced between write and read in
%.
Btw if you go with classic disks, best to think about some small SSDs for SLOG.
I use PCIe cards with two M.2 ports - SLOG mirror one disk on each card, L2ARC
stripe on rest 2. Thinking of some Sun F20 just for SSD - they are for ~70€ on
ebay.
Regards…
I.
On 3 November 2016 at 12:32:12, Gabriele Bulfon ([email protected]) wrote:
Hello,
I'm considering reusing an HP ProLiant DL380e currently running VMware,
scrathing it and reinstalling XStreamOS/illumos (VMware will be moved
elsewhere).
It features 2 hba controllers:
1- HP Dynamic Smart Array B120i RAID controller (with 4 disks, I will use 2 as
a mirrored boot)
2- Smart Array P420 (some TB of disks)
I want to completely bypass hardware array raid and use jbod or similar.
I found documents around saying that I can just configure each disk as a single
array in the controller, obtaining the same effect.
Anyone has suggestions? Any problem I may encounter in this transition?
Should I disable any option on the arrays to disable write caching etc?
Gabriele
----------------------------------------------------------------------------------------
Sonicle S.r.l. : http://www.sonicle.com
Music: http://www.gabrielebulfon.com
Quantum Mechanics : http://www.cdbaby.com/cd/gabrielebulfon
illumos-discuss | Archives | Modify Your Subscription
-------------------------------------------
illumos-discuss
Archives: https://www.listbox.com/member/archive/182180/=now
RSS Feed: https://www.listbox.com/member/archive/rss/182180/21175430-2e6923be
Modify Your Subscription:
https://www.listbox.com/member/?member_id=21175430&id_secret=21175430-6a77cda4
Powered by Listbox: http://www.listbox.com
