--- name: "nfstrace" section: "8" platform: "linux" package: "nfstrace" version: "0.4.3.2+git20200805+b220d04-4" release: "Debian 13 (Trixie)" platforms: ["linux"] url: "https://new.carta.tech/nfstrace" --- # nfstrace(8) NFS and CIFS tracing/monitoring/capturing/analyzing tool ## NAME **nfstrace - NFS and CIFS tracing/monitoring/capturing/analyzing tool** ## SYNOPSIS **nfstrace** \[ **-m** *drain\|live\|dump\|stat* \] \[ **-i** *interface* \] \[ **-f** *filter* \]\ \ \[ **-s** *1..65535* \] \[ **-t** *Milliseconds* \] \[ **-b** *MBytes* \] \[ **-p** *promisc* \] \ \ \[ **-d** *in\|out\|inout* \] \[ **-a** *path#opt1,opt2=val,...* \] \[ **-I** *path* \]\ \ \[ **-O** *path* \] \[ **-C** *'shell command'* \] \[ **-D** *MBytes* \] \[ **-E** *interfaces\|plugins* \]\ \ \[ **-M** *1..4000* \] \[ **-Q** *1..65535* \] \[ **-T** *true\|false* \] \[ **-Z** *username* \] \[ **-v** *0\|1\|2* \] ## DESCRIPTION **nfstrace** performs live Ethernet 1 Gbps – 10 Gbps packets capturing and helps to determine NFS and CIFS procedures in raw network traffic. Furthermore, it performs filtration, dumping, compression, statistical analysis, visualization and provides the API for custom pluggable analysis modules. **nfstrace** captures raw packets from an Ethernet interface using libpcap interface to Linux (LSF) or FreeBSD (BPF) implementations. At the moment it is assumed that libpcap delivers correct TCP and UDP packets. Assembling of IP packets from ethernet frames and IP packets defragmentation are performed in the operating system's kernel. The application has been tested on the workstations with integrated 1 Gbps NICs (Ethernet 1000baseT/Full). Currently **nfstrace** supports the following protocols: Ethernet \> IPv4 \| IPv6 \> UDP \| TCP \> NFSv3 \| NFSv4 \| NFSv4.1 \| CIFSv1 \| CIFSv2 **nfstrace** can operate in four different modes: \- online analysis (**--mode=live**): performs online capturing, filtration and live analysis of detected NFS procedures using a pluggable analysis module or prints out them to **stdout** (**-T** or **--trace** options); \- online dumping (**--mode=dump**): performs online traffic capturing, filtration and dumping to the output file (specified with **-O** or **--ofile** options); \- offline analysis (**--mode=stat**): performs offline filtration of the **.pcap** file that contains previously captured traces and performs analysis using a pluggable analysis module or prints found NFS procedures to **stdout** (**-T** or **--trace** options); \- offline dumping (**--mode=drain**): performs a reading of traffic from the **.pcap** file (specified with **-I** or **--ifile** options), filtration, dumping to the output **.pcap** file (specified with **-O** or **--ofile** options) and removing all the packets that are not related to NFS procedures. **nfstrace** uses libpcap file format for input and output files so any external tool (e.g. **Wireshark**) can be used in order to inspect filtered traces. Since nfstrace internally uses libpcap that provides a portable interface to the native system API for capturing network traffic, filtration is performed in the operating system's kernel. **nfstrace** provides a special option (**-f** or **--filtration**) for specifying custom filters in BPF syntax (see [**pcap-filter**(7)](/pcap-filter/7.md)). The default BPF filter in **nfstrace** is **'port 2049 or port 445'**, which means that each packet that is delivered to user-space from the kernel satisfies the following conditions: it has IPv4 or IPv6 header and it has TCP and UDP header with source or destination port number equals to 2049 (default NFS port) or 445 (default CIFS port). The reality is that this filter is very heavy and support of IPv6 is experimental, so if you want to reach faster filtration of IPv4-only traffic we suggest to use the following BPF filter: **'ip and port 2049 or port 445'.** ## OPTIONS **nfstrace** can usually be run without arguments: in this case default arguments will be used. - **-m, --mode=***live\|dump\|drain\|stat* Set the running mode (see the description above) (default: **live**). - **-i, --interface=***INTERFACE* Listen interface, it is required for live and dump modes (default: **searches for the lowest numbered, configured up interface** **(except loopback)**). - **-f, --filtration=***filter* Specify the packet filter in BPF syntax; for the expression syntax, see [**pcap-filter**(7)](/pcap-filter/7.md) (default: **'port 2049 or port 445'**). - **-s, --snaplen=***1..65535* Set the max length of captured raw packet (bigger packets will be truncated). Can be used only for UDP (default: **65535**). - **-t, --timeout=***milliseconds* Set the read timeout that will be used while capturing (default: **100**). - **-b, --bsize=***MBytes* Set the size of the operating system capture buffer in MBytes; note that this option is crucial for capturing performance (default: **20**). - **-p, --promisc** Put the capturing interface into promiscuous mode (default: **true**). - **-d, --direction=***in\|out\|inout* Set the direction for which packets will be captured (default: **inout**). - **-a, --analysis=***PATH#opt1,opt2=val,...* Specify the path to an analysis module and set its options (if any). - **-I, --ifile=***PATH* Specify the input file for stat mode, **'-'** means **stdin** (default: **nfstrace-{filter}.pcap**). - **-O, --ofile=***PATH* Specify the output file for dump mode, **'-'** means **stdout** (default: **nfstrace-{filter}.pcap**). - **--log=***PATH* Specify the log file (default: **nfstrace.log.{timestamp}**). - **-C, --command=***'shell command'* Execute command for each dumped file. - **-D, --dump-size=***MBytes* Set the size of the dumping file portion, **0** means no limit (default: **0**). - **-E, --enum=***interfaces\|plugins* Enumerate all available network interfaces and and/or all available plugins, then exit; please note that interfaces can't be listed unless nfstrace was built against the recent version of libpcap that supports the **pcap\_findalldevs()** function (default: **none**). - **-M, --msg-header=***1..4000* Truncate RPC messages to this limit (specified in bytes) before passing to a pluggable analysis module (default: **512**). - **-Q, --qcapacity=***1..65535* Set the initial capacity of the queue with RPC messages (default: **4096**). - **-T, --trace** Print collected NFSv3 or NFSv4 procedures, true if no modules were passed with **-a** option. - **-Z, --droproot=***username* Drop root privileges after opening the capture device. - **-v, --verbose=***0\|1\|2* Specify verbosity level (default: **1**). - **-h, --help** Print help message and usage for modules passed with **-a** option, then exit. ## ANALYSIS MODULES ### Operation Breakdown Analyzer Operation Breakdown (OB) analyzer calculates average frequency of NFS and CIFS procedures and computes standard deviation of latency. **$ nfstrace -a libbreakdown.so -h**\ **nfstrace 0.4.0 (Release)**\ **built on Linux-3.16.1-1-generic**\ **by C++ compiler GNU 4.9.1**\ **Usage: ./nfstrace \[OPTIONS\]...**\ Usage example: **$ nfstrace -m stat -a libreakdown.so** Breakdown analyzer produces **.dat** file in the current directory for each detected NFS session that can be visualized using **nst.sh** and **breakdown\_nfsv3.plt** or **breakdown\_nfsv4.plt** (according to NFS version). **$ nst.sh -a breakdown\_nfsv4.plt -d . -p 'breakdown\_10.6.137.47:903\*.dat'** ### Watch Watch plugin mimics old **nfswatch** utility: it monitors NFS and CIFS traffic and displays it in terminal using ncurses. It supports NFSv3, NFSv4, NFSv41, CIFSv1 and CIFSv2. By default watch plugin will update its screen every second, you can specify another timeout in milliseconds: **$ nfstrace -a libwatch.so#2000** ### JSON Analyzer JSON analyzer calculates a total amount of each supported application protocol operation. It accepts TCP-connections on particular TCP-endpoint (host:port), sends a respective JSON to the TCP-client and closes connection. Suggested to be used in **live** mode. **Available options** - **host=***hostname* Network interface to listen (default is to listen all interfaces) - **port=***port* IP-port to bind to (default: **8888**) - **workers=***workers* Amount of worker threads (default: **10**) - **duration=***duration* Max serving duration in milliseconds (default: **500**) - **backlog=***backlog* Listen backlog (default: **15**) **Example of use** Start **nfstrace** in one console: **$ sudo nfstrace -i eth0 -a analyzers/libjson.so#host=localhost**\ ... Make a TCP-request to **nfstrace** in another console to fetch current statistics: **$ telnet localhost 8888**\ Trying 127.0.0.1...\ Connected to localhost.\ Escape character is '^\]'.\ {\ "nfs\_v3":{\ "null":32,\ "getattr":4582,\ ... }, "nfs\_v4":{\ ... },\ ... }Connection closed by foreign host. ## EXAMPLES ### Available options The following command demonstrates available options of the application and plugged analysis modules (attached with **--analysis** or **-a** options). Note that you can pass more than one module here. **nfstrace --help --analysis=libjson.so** ### Online tracing The following command will run **nfstrace** in online analysis mode (specified with **--mode** or **-m** options) without a pluggable analysis module. It will capture NFS and CIFS traffic transferred over TCP or UDP with source or destination port number equals to 2049 and will simply print them out to **stdout** (**-T** or **--trace** options). Capturing ends when **nfstrace** receives **SIGINT** (Control-C). Note that capturing from network interface requires superuser privileges. **nfstrace --mode=live --filtration='ip and port 2049' --trace** ### Online analysis The following command demonstrates running **nfstrace** in online analysis mode. Just like in the previous example it will capture NFS and CIFS traffic transferred over TCP or UDP with source or destination port number equals to 2049 and then it will perform Operation Breakdown analysis using pluggable analysis module **libbreakdown.so.** **nfstrace -m live -f 'ip and port 2049' --analysis=libbreakdown.so** ### Online dumping and offline analysis The following example demonstrates running **nfstrace** in online dumping and offline analysis modes. At first **nfstrace** will capture NFS traffic transferred over TCP or UDP with source or destination port number equals to 2049 and will dump captured packets to **dump.pcap** file (specified with **--ofile** or **-O** options). At the second run **nfstrace** will perform offline Operation Breakdown analysis using pluggable analysis module **libbreakdown.so.** **# Dump captured packets to dump.pcap**\ **nfstrace -m dump -f 'ip and port 2049' --ofile=dump.pcap**\ **# Analyse dump.pcap using libbreakdown.so**\ **nfstrace -m stat --ifile=dump.pcap -a libbreakdown.so** ### Online dumping, compression and offline analysis The following example demonstrates running **nfstrace** in online dumping and offline analysis modes. Since dump file can easily exhaust disk space, compression makes sense. At first **nfstrace** will capture NFS traffic transferred over TCP or UDP with source or destination port number equals to 2049 and will dump captured packets to **dump.pcap** file. Note that compression is done by the external tool (executed in script passed with **--command** or **-C** options) and it will be executed when capturing is done. The output file can be inspected using some external tool. At the second run **nfstrace** will perform offline analysis. Again, the external tool (**bzcat** in this example) is used in order to decompress previously saved dump. **nfstrace** will read **stdin** (note the **-I –** option) and perform offline analysis using Operation Breakdown analyzer. **# Dump captured procedures to dump.pcap file.**\ **# Compress output using bzip2 when capturing ends.**\ **nfstrace -m dump -f 'ip and port 2049' -O dump.pcap --command 'bzip2 -f -9'** **# Extract dump.pcap from dump.pcap.bz2 to stdin.**\ **# Read stdin and analyze data with libbreakdown.so module.**\ **bzcat dump.pcap.bz2 \| nfstrace -m stat -I - -a libbreakdown.so** ### Online dumping with file limit, compression and offline analysis This example is similar to the previous one except one thing: output dump file can be very huge and cause problems in some situations, so **nfstrace** provides the ability to split it into parts. At first **nfstrace** will be invoked in online dumping mode. Everything is similar to the previous example except **-D** (**--dump-size**) option: it specifies the size limit in MBytes, so dump file will be split according to this value. At the second run **nfstrace** will perform offline analysis of captured packets using Operation Breakdown analyzer. Please note that only the first dump file has the pcap header. **# Dump captured procedures multiple files and compress them.**\ **nfstrace -m dump -f 'ip and port 2049' -O dump.pcap -D 1 -C bzip2 -f -9** **# get list of parts in the right order:**\ **# dump.pcap.bz2**\ **# dump.pcap-1.bz2**\ **# dump.pcap-2.bz2**\ **parts=$(ls dump.pcap\*.bz2 \| sort -n -t - -k 2)** **# Extract dump.pcap from main dump.pcap.bz2 and parts to stdin.**\ **# Read stdin and analyze data with libbreakdown.so module.**\ **bzcat $parts \| nfstrace --mode=stat -I - --analysis=libbreakdown.so** ### Visualization This example demonstrates the ability to plot graphical representation of data collected by Operation Breakdown analyzer. **nst.sh** is a shell script that collects data generated by analyzers and passes it to gnuplot script specified with **-a** option. **breakdown.plt** is a gnuplot script that understands output data format of Operation Breakdown analyzer and generates **.png** files with plots. Note that **gnuplot** must be installed. **# Extract dump.pcap from dump.pcap.bz2 to stdin.**\ **# Read stdin and analyze data with libbreakdown.so module.**\ **bzcat trace.pcap.bz2 \| nfstrace -m stat -I - -a libbreakdown.so** **# Generate plot according to \*.dat files generated by**\ **# libbreakdown.so analyzer.**\ **nst.sh -a breakdown.plt -d . -p 'breakdown\*.dat' -v** ## FILES - API headers **/usr/include/nfstrace/api/** - Pluggable Analysis Modules (PAMs) **/usr/lib/nfstrace/** ## BUGS Any problems, bugs, questions, desirable enhancements, etc. should be sent to **\** ## AUTHORS Vitali Adamenka **\** Yauheni Azaranka **\** Alexey Costroma **\** Dzianis Huznou **\** Pavel Karneliuk **\** Andrey Kuznetsov **\** Mikhail Litvinets **\** Ilya Storozhilov **\** ## SEE ALSO [**bpf**(4)](/bpf/4.md), [**pcap**(3)](/pcap/3.md), [**nfsstat**(8)](/nfsstat/8.md), [**pcap-filter**(7)](/pcap-filter/7.md).