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Raid 10 DM & Distributed sparring
Hi,
What is the minimum number of disks required for raid10 dm on these units?
also does this differ from raid 10 with distributed sparring ?
I would like 6 x 800GB SSD WI in tier1 but with dual redundancy akin to raid 6. it would look like i need 7 disks for distributed sparring (traditional hot spare)
but the dual mirror requirements are not clear to me.
with 6 disks i thought you could have a 3 write penalty with 33% usable space 3 disks per pair instead of 2
overall configuration is as follows
scv3020
6 x 800gb SSD WI - tier 1 raid10dm
10 x 1.92TB SSD RI - tier 2 - raid 6
10 x 2.4TB HDD 10K - tier 3 - raid 6
I would like dual redundant array configuration. also can someone critique this build? i have run live optics and believe sized accordingly.
thanks
DELL-Bob Mi
230 Posts
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August 26th, 2018 09:00
First, let me answer your questions:
What is the minimum number of disks required for raid10 dm on these units?
The minimum is 3 Disks + 1 Spare. A Raid 10 Dual mirror needs at least 3 disks
also does this differ from raid 10 with distributed sparring ?
No, You still need to have the same amount of disks in case of a failure
Please refer to Dell Storage Center OS 7.3 technical publications where this a link to a document and video on Distributed Sparing
In regards to how you configure your system I generally recommend speaking to a Dell Storage Architech to make sure you are not under-sizing your system.
Create a Storage Type
Modify the redundancy for each tier as needed.
For single-redundant RAID levels, select Redundant.
For dual-redundant RAID levels, select Dual Redundant.
just_it_things
2 Posts
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August 26th, 2018 11:00
Hi,
I've read those papers linked. It just was not clear what disks were required.
I find the SC somewhat confusing and would prefer to get my hands on it to play around with it.
I believe the unit has been sized accordingly after running live optics. Also my understanding is that in hybrid-flash mode data progression is run regularly to avoid filling the raid10 set
Will the unit group the WI & RI SSDs in Tier1 or will it split them off to tier1 & tier2?
Is there any performance advantage to having both types of SSD in tier1 with regard to data progression?
thanks
DELL-Bob Mi
230 Posts
0
August 26th, 2018 12:00
You are correct that since this will be a hybrid system it will flush the data to Tier 2 regularly to avid Tier 1 from filling
Will the unit group the WI & RI SSDs in Tier1 or will it split them off to tier1 & tier2?
Yes, disks are assigned to disk classes so the WI-SSD will be assigned to Tier 1, and the RI-SSD will be assigned to Tier 2
Is there any performance advantage to having both types of SSD in tier1 with regard to data progression?
The system will not allow the 2 types to be combined in one Tier