---
name: "pcp-nfsiostat"
section: "1"
platform: "linux"
package: "pcp"
version: "7.2.2-2"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/pcp-nfsiostat"
---

# pcp-nfsiostat(1)

Emulate iostat for NFS mount points using /proc/self/mountstats

## NAME

**pcp-nfsiostat** - Emulate iostat for NFS mount points using /proc/self/mountstats

## SYNOPSIS

**pcp** \[**pcp options**\] **nfsiostat** \[**-a** **archive**\] \[**-S** **start**\] \[**-T** **finish**\] \[**-O** **origin**\] \[**-s** **samples**\] \[**-t** **interval**\] \[**-Z** **--timezone**\] \[**-h** **--host**\] \[**-z** **--hostzone**\] \[**-V** **Version**\]

## DESCRIPTION

The **pcp-nfsiostat** command reports client-side **Network File System (NFS)** I/O statistics for each mounted NFS filesystem. For every NFS mountpoint, the output consists of a summary section followed by detailed read and write statistics blocks. These statistics include operation rates, data throughput, latency, retransmissions, queueing delays, and error counts. By default, **pcp-nfsiostat** monitors NFS mountpoints on the local host and reports live metrics collected via the  **PCP NFS PMDA** , or from an alternative host if specified. When an archive is specified, historical metrics are reported instead.

## OUTPUT FORMAT

Statistics are reported per mounted NFS filesystem using the following layout:

```
server:/export mounted on /mount/point:
           ops/s       rpc bklog
           0.017           0.000
read:              ops/s   kB/s   kB/op   retrans   avg RTT (ms)   avg exe (ms)   avg queue (ms)   errors
                   ...
write:             ops/s   kB/s   kB/op   retrans   avg RTT (ms)   avg exe (ms)   avg queue (ms)   errors
                   ...
```

## FIELD DESCRIPTIONS

- **ops/s**

  Number of NFS operations performed per second.

- **rpc bklog**

  Average number of RPC requests waiting to be transmitted.

- **kB/s**

  Kilobytes transferred per second.

- **kB/op**

  Average number of kilobytes transferred per operation.

- **retrans**

  Number of RPC retransmissions and the retransmission percentage.

- **avg RTT (ms)**

  Average round-trip time in milliseconds for RPC requests.

- **avg exe (ms)**

  Average execution time in milliseconds spent servicing requests on the server.

- **avg queue (ms)**

  Average time in milliseconds spent waiting in the RPC transmission queue.

- **errors**

  Number of failed operations and failure percentage.

## OPTIONS

- **-a**, **--archive** archive

  Fetch NFS I/O statistics from the specified PCP archive.

- **-s**, **--samples** samples

  Number of samples to collect before exiting.

- **-t**, **--interval** interval

  Set the interval between two samples. The default is one second.

- **-S**, **--start** start

  Set the start of the time window when replaying an archive.

- **-T**, **--finish** finish

  Set the end of the time window when replaying an archive.

- **-O**, **--origin** origin

  Set the initial sample time within the time window when replaying an archive.

- **-h**, **--host** host

  Fetch NFS I/O statistics from the specified host.

- **-z**, **--hostzone**

  Set the reporting timezone to the local timezone of the metrics source.

- **-Z**, **--timezone** tz

  Set the reporting timezone.

- **-V**, **--version**

  Display version information and exit.

- **-?**, **--help**

  Display usage information and exit.

## NOTES

**pcp-nfsiostat** reports client-side NFS statistics collected from the kernel and exposed via the PCP NFS PMDA. The output format and metrics are similar to those reported by the [**nfsiostat**(1)](/nfsiostat/1.md) tool from the nfs-utils package.

## PCP ENVIRONMENT

Environment variables with the prefix **PCP\_** are used to parameterize the file and directory names used by PCP. On each installation, the file */etc/pcp.conf* contains the local values for these variables. The **$PCP\_CONF** variable may be used to specify an alternative configuration file, as described in [**pcp.conf**(5)](/pcp.conf/5.md).

For environment variables affecting PCP tools, see [**pmGetOptions**(3)](/pmGetOptions/3.md).

## SEE ALSO

[**PCPIntro**(1)](/PCPIntro/1.md), [**pcp**(1)](/pcp/1.md), [**nfsiostat**(1)](/nfsiostat/1.md), [**environ**(7)](/environ/7.md).