CEPH-SYN(8) Ceph CEPH-SYN(8)

# [NAME](#NAME)

ceph-syn - ceph synthetic workload generator

# [SYNOPSIS](#SYNOPSIS)

```
ceph-syn [ -m monaddr:port ] --syn command ...
```

# [DESCRIPTION](#DESCRIPTION)

**ceph-syn** is a simple synthetic workload generator for the Ceph distributed file system. It uses the userspace client library to generate simple workloads against a currently running file system. The file system need not be mounted via [ceph-fuse(8)](/man/enterprise-packages/ceph-19/ceph-fuse.8) or the kernel client.

One or more **--syn** command arguments specify the particular workload, as documented below.

# [OPTIONS](#OPTIONS)

[**-d**](#d)

Detach from console and daemonize after startup.

[**-c ceph.conf, --conf=ceph.conf**](#c)

Use *ceph.conf* configuration file instead of the default **/etc/ceph/ceph.conf** to determine monitor addresses during startup.

[**-m monaddress\[:port\]**](#m)

Connect to specified monitor (instead of looking through **ceph.conf**).

[**--num\_client num**](#num_client)

Run num different clients, each in a separate thread.

[**--syn workloadspec**](#syn)

Run the given workload. May be specified as many times as needed. Workloads will normally run sequentially.

# [WORKLOADS](#WORKLOADS)

Each workload should be preceded by **--syn** on the command line. This is not a complete list.

[**mknap** *path* *snapname*](#mknap)

Create a snapshot called *snapname* on *path*.

[**rmsnap** *path* *snapname*](#rmsnap)

Delete snapshot called *snapname* on *path*.

[**rmfile** *path*](#rmfile)

Delete/unlink *path*.

[**writefile** *sizeinmb* *blocksize*](#writefile)

Create a file, named after our client id, that is *sizeinmb* MB by writing *blocksize* chunks.

[**readfile** *sizeinmb* *blocksize*](#readfile)

Read file, named after our client id, that is *sizeinmb* MB by writing *blocksize* chunks.

[**rw** *sizeinmb* *blocksize*](#rw)

Write file, then read it back, as above.

[**makedirs** *numsubdirs* *numfiles* *depth*](#makedirs)

Create a hierarchy of directories that is *depth* levels deep. Give each directory *numsubdirs* subdirectories and *numfiles* files.

[**walk**](#walk)

Recursively walk the file system (like find).

# [AVAILABILITY](#AVAILABILITY)

**ceph-syn** is part of Ceph, a massively scalable, open-source, distributed storage system. Please refer to the Ceph documentation at <https://docs.ceph.com> for more information.

# [SEE ALSO](#SEE_ALSO)

ceph <>(8), ceph-fuse <>(8)

# [Copyright](#Copyright)

2010-2014, Inktank Storage, Inc. and contributors. Licensed under Creative Commons Attribution Share Alike 3.0 (CC-BY-SA-3.0)

October 7, 2026 dev

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Document: ceph-syn(8) from ceph-19 19.2.6-r5 (Chainguard OS)
Source: https://github.com/ceph/ceph.git