Vsan with 3 blades

[tdubb123]

I am thinking of getting 3 cisco E series blades in a vsan configuration

if one blade can take a max of 2TB, how much can I get from my vsan from all 3 blades?

[vervoortjurgen]

depends on your configuration

if som servers need RAID 10 or RAID 5

also keep in mind you need SSD disk for vsan to work

in this article there are some formules

https://www.vmware.com/files/pdf/products/vsan/VSAN_Design_and_Sizing_Guide.pdf

[tdubb123]

It's going to be raid5.

Each blade can go up to 2tb storage but only 2 disks per blade

On Sunday, January 25, 2015, vervoort jurgen <communities-emailer@vmware.com>

[vervoortjurgen]

that's just it. blades only go with 2 disk.

i don't have much experience with vsan but you also need at least 1 ssd disk per host. so leave you with 1 hd disk.

so 3 blade with 1x 2TB disk raid 5 config will habe 4 TB datastore capability

[tdubb123]

I think the blade can take 2 drives, 1ssd and 1 sas. Each 1tb

Will the ssd count as part of the vsan

On Sunday, January 25, 2015, vervoort jurgen <communities-emailer@vmware.com>

[vervoortjurgen]

no only the magnetic disks are counted for datastore usage

"The Virtual SAN distributed datastore capacity is determined by aggregating the disk groups situated across multiple hosts that are members of a vSphere cluster and by the size of the magnetic disks. Disk groups consist of a combination of flash-based devices and magnetic disks pooled together, but only the usable capacity of the magnetic disks counts toward the total capacity of the Virtual SAN datastore. The capacity of the flash-based devices is specifically dedicated to the caching layer of Virtual SAN."

and the flash for read and write performance. so you dont need 1TB SSD you can go smaller like 400 GB should be enough

"The Virtual SAN distributed flash layer optimizes virtual machine and application performance by providing read caching and write buffering in front of all magnetic disks. Capacity is divided into two segments: 70 percent for read cache and 30 percent as write buffer."

[tdubb123]

thank you for your response.

here is the cisco E series spec. looks like I can only get a maximum of 1TB sas drive per blade. and with 3 blades, on a vsan on a raid5, would that mean I am only going to get 2TB max on the vsan?

[HawkieMan]

On those blades, i would actually add a third disk, PCI-Express SSD. This way you will have 2 SSDs and 1 SAS/SATA drive.

[vervoortjurgen]

good point from HawkieMan

didnt think about that

then you can have 2x 1TB disk indeed

[HawkieMan]

I am using the same blades, and the PCI-Express SSDs are working very well, and it allows me to have 2 SAS Disks in the slots.

Dont forget to reward answers as correct or helpful 🙂

[tdubb123]

i thought it can only have 2 hard disks. Where do you put the ssd? Did you get 2TB sas disks on your blades?

What do you get for total storage for vsan?

[tdubb123]

it does not look like pci express is available for the single wide blade. so still limited to 2 HDD/blade

If I were to do 3 blades and 2HDD each

each blade, 200GB ssd, 1TB sas

Will that give me a total of 3TB raw?