Metadata servers — application workload method worksheet

Use this worksheet to calculate the number of metadata servers that are required in your environment, based on the number of hard disk drives that are available to SAN File System.

Application workload characteristics

Primary applications types (for example, database or mail server)                               
Average file size, per application                               
Size of the hotset (number of objects), per application                               
Client platforms                               
Number of clients, per application                               
Average directory size                               
Does the application perform a dirwalk?                               
Will objects be shared (read/write) among multiple clients?                               
Transaction rate (for example, connects per second, or orders per second), per application                               

Average metadata server operations per second

Use the following table to estimate the average FOP and metadata server OP percentage:
Application type Typical metric Average FOP/APPOP Average metadata server OP/FOP
Mail server Mails per second 20 3%
OLTP database back end Transactions per second 2 5%
Data Warehouse database back end Tuples per second 0.1 10%
Office workgroup Documents per second 10 1%
Web server Connections per second 5 10%
Web proxy Pages per second 15 10%
Peer-to-peer Files per second 12 10%
Network File System Serving Megabytes per second 30 10%
Common Internet File System Serving Megabytes per second 30 10%
Compile Build (Development) Files built per second 10 5%
User Folder Serving Files used per second 5 3%
Calculate the average metadata server operations per second:
( Transaction rate * average FOPs ) * metadata server OPs           

Adjustment factor

Average file size larger than 500 Mb + 20%           
File hotset less than 10 K  
Windows® clients + 20%  
Number of clients (uniform) * number of clients  
Average directory size larger than 100 objects  
Special application dirwalk + 20%  
Object sharing read/writes + 20%  

Number of required metadata servers

highest metadata server OP / 1 500           

Parent topic: Worksheets

Related tasks
Sizing the metadata servers based on application workload

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