HBA or raid-controller for OSD
Serg
4 Posts
October 19, 2018, 6:58 amQuote from Serg on October 19, 2018, 6:58 amHello
First of all I want to thank you for the great product - PetaSAN.
We plan to use 1 SSD for journal and 5 HDD for OSD in each server.
You wrote several times on the forum that it is desirable to use a controller with a write back cache to improve HDDs performance. Can you please advise the controller model. For example, would "LSI Logic MegaRAID SAS 9361-8i (2G cache)" be a good choice? Should i use BBU for controller? How exactly to present disks to the system? Should i create multiple Raid1 arrays, each of which will consist of a single HDD? Or should i merge all HDD into one Raid0 or Raid5 array? How to present journal SSD to the system using a raid-controller?
Thank you!
Hello
First of all I want to thank you for the great product - PetaSAN.
We plan to use 1 SSD for journal and 5 HDD for OSD in each server.
You wrote several times on the forum that it is desirable to use a controller with a write back cache to improve HDDs performance. Can you please advise the controller model. For example, would "LSI Logic MegaRAID SAS 9361-8i (2G cache)" be a good choice? Should i use BBU for controller? How exactly to present disks to the system? Should i create multiple Raid1 arrays, each of which will consist of a single HDD? Or should i merge all HDD into one Raid0 or Raid5 array? How to present journal SSD to the system using a raid-controller?
Thank you!
admin
2,930 Posts
October 19, 2018, 9:16 amQuote from admin on October 19, 2018, 9:16 amYes to get high IOPS , you would need an all flash solution (recommended) or use controller with cache with spinning disks. If your applications does just backups or video streaming..then in is not IOPS sensitive and would do fine with straight hdds.
With hdds, typically you can load more disks per host (16-24) if you have good hardware, still keeping the 1:4-5 ratio with SSD journal. With all flash you generally do not go above 8-10.
Yes BBU is important to have
I cannot recommend on specific models, but generally they all work well. Some (few) models allow you to use write back cache in jbod mode, others you will need to set up single disk RAID-0 volumes. Do not create arrays. Ceph works best the more OSDs it has.
Yes to get high IOPS , you would need an all flash solution (recommended) or use controller with cache with spinning disks. If your applications does just backups or video streaming..then in is not IOPS sensitive and would do fine with straight hdds.
With hdds, typically you can load more disks per host (16-24) if you have good hardware, still keeping the 1:4-5 ratio with SSD journal. With all flash you generally do not go above 8-10.
Yes BBU is important to have
I cannot recommend on specific models, but generally they all work well. Some (few) models allow you to use write back cache in jbod mode, others you will need to set up single disk RAID-0 volumes. Do not create arrays. Ceph works best the more OSDs it has.
Ste
125 Posts
October 19, 2018, 10:58 amQuote from Ste on October 19, 2018, 10:58 am
Quote from admin on October 19, 2018, 9:16 am
I cannot recommend on specific models, but generally they all work well.
Well, I identified the "Adaptec 2244100-R 5805 8-Channel SATA/SAS 512MB PCI-Express LP RAID Controller", do you think would it be compatible/adequate for PetaSAN ?
Quote from admin on October 19, 2018, 9:16 am
I cannot recommend on specific models, but generally they all work well.
Well, I identified the "Adaptec 2244100-R 5805 8-Channel SATA/SAS 512MB PCI-Express LP RAID Controller", do you think would it be compatible/adequate for PetaSAN ?
admin
2,930 Posts
October 19, 2018, 11:24 amQuote from admin on October 19, 2018, 11:24 amYou need to try it in combination with your hardware + workload. The more internal RAM the better.
You need to try it in combination with your hardware + workload. The more internal RAM the better.
Ste
125 Posts
October 26, 2018, 10:49 amQuote from Ste on October 26, 2018, 10:49 am<deleted>
<deleted>
Last edited on October 26, 2018, 10:52 am by Ste · #5
HBA or raid-controller for OSD
Serg
4 Posts
Quote from Serg on October 19, 2018, 6:58 amHello
First of all I want to thank you for the great product - PetaSAN.
We plan to use 1 SSD for journal and 5 HDD for OSD in each server.
You wrote several times on the forum that it is desirable to use a controller with a write back cache to improve HDDs performance. Can you please advise the controller model. For example, would "LSI Logic MegaRAID SAS 9361-8i (2G cache)" be a good choice? Should i use BBU for controller? How exactly to present disks to the system? Should i create multiple Raid1 arrays, each of which will consist of a single HDD? Or should i merge all HDD into one Raid0 or Raid5 array? How to present journal SSD to the system using a raid-controller?Thank you!
Hello
First of all I want to thank you for the great product - PetaSAN.
We plan to use 1 SSD for journal and 5 HDD for OSD in each server.
You wrote several times on the forum that it is desirable to use a controller with a write back cache to improve HDDs performance. Can you please advise the controller model. For example, would "LSI Logic MegaRAID SAS 9361-8i (2G cache)" be a good choice? Should i use BBU for controller? How exactly to present disks to the system? Should i create multiple Raid1 arrays, each of which will consist of a single HDD? Or should i merge all HDD into one Raid0 or Raid5 array? How to present journal SSD to the system using a raid-controller?
Thank you!
admin
2,930 Posts
Quote from admin on October 19, 2018, 9:16 amYes to get high IOPS , you would need an all flash solution (recommended) or use controller with cache with spinning disks. If your applications does just backups or video streaming..then in is not IOPS sensitive and would do fine with straight hdds.
With hdds, typically you can load more disks per host (16-24) if you have good hardware, still keeping the 1:4-5 ratio with SSD journal. With all flash you generally do not go above 8-10.
Yes BBU is important to have
I cannot recommend on specific models, but generally they all work well. Some (few) models allow you to use write back cache in jbod mode, others you will need to set up single disk RAID-0 volumes. Do not create arrays. Ceph works best the more OSDs it has.
Yes to get high IOPS , you would need an all flash solution (recommended) or use controller with cache with spinning disks. If your applications does just backups or video streaming..then in is not IOPS sensitive and would do fine with straight hdds.
With hdds, typically you can load more disks per host (16-24) if you have good hardware, still keeping the 1:4-5 ratio with SSD journal. With all flash you generally do not go above 8-10.
Yes BBU is important to have
I cannot recommend on specific models, but generally they all work well. Some (few) models allow you to use write back cache in jbod mode, others you will need to set up single disk RAID-0 volumes. Do not create arrays. Ceph works best the more OSDs it has.
Ste
125 Posts
Quote from Ste on October 19, 2018, 10:58 amQuote from admin on October 19, 2018, 9:16 amI cannot recommend on specific models, but generally they all work well.
Well, I identified the "Adaptec 2244100-R 5805 8-Channel SATA/SAS 512MB PCI-Express LP RAID Controller", do you think would it be compatible/adequate for PetaSAN ?
Quote from admin on October 19, 2018, 9:16 amI cannot recommend on specific models, but generally they all work well.
Well, I identified the "Adaptec 2244100-R 5805 8-Channel SATA/SAS 512MB PCI-Express LP RAID Controller", do you think would it be compatible/adequate for PetaSAN ?
admin
2,930 Posts
Quote from admin on October 19, 2018, 11:24 amYou need to try it in combination with your hardware + workload. The more internal RAM the better.
You need to try it in combination with your hardware + workload. The more internal RAM the better.
Ste
125 Posts
Quote from Ste on October 26, 2018, 10:49 am<deleted>
<deleted>