eG Monitoring
 

Measures reported by VnxCifsStatTest

EMC VNX uses Common Internet File System (CIFS) protocol as an open standard for network file service. CIFS is a file access protocol designed for the Internet and is based on the Server Message Block (SMB) protocol that the Microsoft Windows operating system uses for distributed file sharing. The CIFS protocol lets remote users access file systems over the network. You can configure the CIFS protocol on a data mover to enable that data mover to allow remote users to access the file systems that it contains via CIFS. By continuously monitoring the CIFS operations on every data mover, you can easily identify that data mover on which CIFS is most ineffective/problematic. This is where, the VnxCifsStatTest test helps.

This test monitors the CIFS reads and writes performed on each data mover in the VNX system and reports the following:

  • The number of CIFS protocol connections to the data mover;
  • The number of CIFS files that are currently open on the data mover;
  • How well the I/O operations were performed using the CIFS protocol, and whether any delays were noticed;
  • The total amount of data transacted when performing CIFS reads and writes

These statistics will not only enable administrators to promptly detect current or probable latencies in I/O operations when using CIFS, but will also help them figure out which I/O activity was most latent - i.e., whether reading or writing - and on which data mover.

The measures made by this test are as follows:

Measurement Description Measurement Unit Interpretation
Total_operations Indicates the rate at which operations were performed by users through CIFS protocol to access this Data Mover. Ops/sec A high value is desired for this measure. A consistent decrease in this value could indicate a processing bottleneck.
Read_operations Indicates the rate at which read operations were performed on this data mover using the CIFS protocol. Ops/Sec If the value of the Total_operations measure dips consistently, then, you may want to time-correlate that measure with the value of these two measures to know what is causing the steady decline in CIFS performance - read operations or write operations? This way, you can figure out when the slowdown actually occurred - when reading or when writing?
Write_operations Indicates the rate at which write operations were performed by users through CIFS protocol on this Data Mover. Ops/Sec
Read_data Indicates the rate at which the data is read using CIFS protocol from this Data Mover. KiB/Sec Ideally, the value of these measures should be high. A consistent decrease in their value is an indication of a processing bottleneck.

When users complaint of delays when accessing the file system using CIFS, you can compare the value of each of these measures across data movers to know which data mover is experiencing the slowdown. You can then compare the value of these measures for that data mover to know when the slowdown occurred - when reading from or when writing to the file system?

Write_data Indicates the rate at which the data is written to this data mover using CIFS protocol. KiB/Sec
Avg_read_data Indicates the average amount of data read from this data mover per read operation. KiB/Operation Compare the value of this measure across data movers to know which data mover is taking the longest to complete a read operation. You can then begin to focus on that data mover and closely track how this measure is behaving for that data mover. A consistent decrease in the value of this measure could indicate problems when reading from the file systems in that data mover.
Avg_write_data Indicates the average amount of data written to this data mover per write operation. KiB/Operation Compare the value of this measure across data movers to know which data mover is taking the longest to complete a write operation. You can then begin to focus on that data mover and closely track how this measure is behaving for that data mover. A consistent decrease in the value of this measure could indicate problems when writing into the file systems in that data mover.
Protocol_connections Indicates the number of CIFS protocol connections to this Data Mover. Number  
Open_files Indicates the number of CIFS files that are currently open on this Data Mover. Number