Forums

Home / Forums

You need to log in to create posts and topics. Login · Register

building full SSD cluster

Hi, we are looking at solutions for a production data centre refresh.

I would like to better understand when using full SSD cluster if the following is correct and sized correct.

solution will be starting with 4x Dell R740DX servers, each has:

128GB Ram,Dual CPU 8 core 3.2Ghz, dual HBA adapters split 4:20,4x Write intensive SSD 800GB,20x read / write SSD 1TB

2x 25Gbps ports (back end storage), 8x 10Gbps ports front end storage / iSCSI / management, 4x 800GB for Journal, 20x 1TB for OSD

separate switches for back end storage / front end / iSCSI

running in a VMWare environment with a number of Windows 2019 VM's with MS SQL 2016 SP2 servers as their storage cluster.

backup technology will be Veeam.

my questions are:

Does the above spec seem reasonable per node? as a starting position to run 4 nodes with 3 replicas? (is 3 replicas too much when using all SSD?)

As all the storage is SSD am I correct in adding the 4x Journal SSD discs when the OSD discs are all SSD and not 15K, 10K, SATA for example?

will 128GB Ram per node suffice.

I know I have more 10Gbps interfaces than I need, we have allowed this number in case PetaSan is not a good fit and we have to go VMWare VSAN for example and load a hypervisor on the boxes direct (hopefully not the case).

Any guidance appreciated.

No need for the journals, just use all SSD OSD without journal

3x replica is the best practice

128G ram is good

Do try to get good enterprise SSDs, some that work well:

Samsung: 863 883 963 983 1633 1725
Intel: S3510 P3600 S3610 P3700 S4500 S4600

Else make sure they have good sync write speed via the PetaSAN blue console menu disk test + good power loss protection and durability, dwpd.

Also recommend you create your vmdk as thick eager zero, else initial performance may be slow in the beginning + for all SSD, it may be better to increase the ESX queue depths per lun for best performance, we are updating our vmware docs to reflect these recommendation soon.

Hi, thank you for your quick reply, confirming along with tips for VMWare. look forward to reading the updated documentation.

In regards VMware ESXi I noted mention that 6.7 U3 may have some issue so planning to run with Enterprise edition of 6.7 U2.

 

All SSD discs are enterprise grade with the following spec:

TOSHIBA PX05SVB096Y Revision AS0E

ENTERPRISE GRADE

Capacity: 960GB

Speed: Solid State Memory

Interface Types: SAS Serial Attached SCSI

Form Factor: 2.5inx15mm SFF Server Drive

Sector Size: 512 / 512e

Sustained Throughput: 1900/850

Electrical Interface: SAS-3 Serial Attached SCSI v3 - 12.0Gbps

SSD Type: MLC

SSD Endurance DWPD: Enterprise Mixed Use

 

Once again, thank you for your assistance and a great product.