3 Posts
0
1677
August 7th, 2020 22:00
OverProvisioning for SSDs in RAID1 with PERC h730p
We have a new Dell R540 Server with 2 Pairs of SAS SSDs - one pair for OS (240GB Intel S4610 ) and the other for Database (480GB KIOXIA PMV-5). There are 4 more SAS HDDs which will be configured in RAID5 for running virtual workloads. We've got a PERC h730p raid contoller
We want to configure the SSDs in RAID 1 for Performance and Reliability. There are multiple articles suggesting Over-Provisioning SSDs, so I have below questions before I go ahead with configuring RAID 1 arrays for SSDs:
1. Is Over Provisioning really needed? This server will run virtualized workloads (mix of Windows and Linux servers running on HyperV).
2. Does h730p support OP in RAID 1 mode?
3. Are there any specific optimizations that can be done for optimizing Performance and Endurance of these SSDs in RAID 1?
There's very little or no literature available to understand this. So answers for this may help a lot of others.
Thanks
DELL-Joey C
Moderator
•
3.9K Posts
0
August 10th, 2020 01:00
Hi,
At present time, over-provisioning are built-in into SSD, so there is no settings need to be done at hardware level; https://dell.to/2DJOF4J. Though, the feature is within Dell SSD drive info that I can find. I did a quick search on Intel S4610, it does say OP is too in the drives itself, which is the firmware. For Performance and Endurance of SSD, they need not to be optimize as they as automatically done by the RAID controller firmware and SSD firmware.
https://dell.to/2DJOF4J
Let me know if it helps.
DELL-Charles R
Moderator
•
4.4K Posts
0
August 10th, 2020 06:00
Hello not_literally,
Any unclaimed space will automatically be used by the controller as dynamic over-provisioning.
Please let me know if this helps.
DELL-Charles R
Moderator
•
4.4K Posts
0
August 10th, 2020 06:00
Hello not_literally,
The unallocated space will be available for the drives over-provisioning.
not_literally
3 Posts
0
August 10th, 2020 05:00
Hello,
It is said that in contrast to HDDs, all SSDs already provide a basic level OP by using difference between the advertised capacity in GiB vs GB (7.37%) as OP.
Additionally, Enterprise SSDs provide additionally OP by taking away some of the storage. E.g a 480 GB SSD is made out of a 512 GB SSD and 32GBs(6.25%) are used as OP.
So in all, 13.62% is Over Provisioned by default.
Referring to Intel's Documentation, which mentions stats for S4610 also, it says that 10% OP(over and above 13.62%) will give a significant improvement in Endurance. Unfortunately, could find such stats for KIOXIA PM5-V.
So, wanted to confirm whether free space inside RAID volume is still available as Dynamic OP space?
I'm a bit cautious here because its my first experience with SSDs on RAID and I don't want to run into performance issues 2 Years later.
Thanks for all the patience!
not_literally
3 Posts
0
August 10th, 2020 06:00
Hello @Dell -Charles R ,
Could you confirm that if I create a Partition of full size inside RAID1 volume and if the Partition has 50% free space, that space is used by Controller for Dynamic Over-Provisioning?
OR
You mean that if I leave 10% space unallocated on RAID1 array, that 10% space will be automatically used by controller for Dynamic Over-Provisioning?
Thanks for your reply!