Running rsync on ESXi is not a new topic, there are a number of users in the community who have made this work. One well-known user, Dave Mishchenko, who runs vm-help and recently authored VMware ESXi: Planning, Implementation, and Security, provides an rsync binary that can be downloaded to run on ESXi. Not that I did not trust Dave and the source of his rsync binary, but I wanted to compile my own and understand the process Dave took to get to a compatible rsync for ESXi. In talking to Dave, I found out the binary was actually provided by a VMTN user, named glim who had noted some of the details in this VMTN thread.

The user basically created a statically linked versus a dynamically linked version of rsync which runs without relying on libraries that may or may not be present on ESXi. My initial attempts failed using both a 32/64bit CentOS 5.5 and latest version of rsync 3.0.7 and 3.0.3. The compilation of rsync was successful, but upon executing on ESXi, it immediately had a segmentation fault. I started to think there might be some dependencies in libraries that were used to compile rsync that I was missing. I was also in conversation with Alain Spineux, creator of MKSBackup regarding this same topic and he had found a way to compile rsync based on the article Hacking ESXi by Stjepan Groš.

Stejepan found that using CentOS 3.9, one could compile both statically and dynamically linked binaries without any modifications to ESXi. Though Stejepan did not provide the steps to compile rsync, it is relatively simple to do so. I also found that you do not need to use older 3.0.3 release of rsync, you can use the latest version which is 3.0.7 as of writing this article.

Before we get started, let me remind you of the disclaimer:

Step 1

Download and install CentOS 3.9 i386 - You can find a list of download sites here

Step 2

With a default installation of CentOS 3.9, you just need to get GCC installed

yum -y install gcc

Step 3

Next you will need to download the latest version of rsync which is 3.0.7 here and SCP it to your CentOS system

Step 4

Next you will now extract the contents of the rsync-3.0.7.tar.gz

tar -zxvf rsync-3.0.7.tar.gz

Step 5

Now you will change into the rsync-3.0.7 directory and run the configure command


Step 6

Now you will run the make command which will compile rsync, but you will also be passing in additional flags to create a statically linked binary

make CFLAGS="-static" EXEEXT="-static"

Step 7

Finally, you will need to run the strip utility which discards all symbols from object files

strip rsync-static

You now have a self-contain rsync binary labeled rsync-static found in the current working directory

Next up, you will SCP the rsync-static binary to your ESX(i) host and set the appropriate permissions to execute. I decided to temporarily store it in /tmp, but if you want the binary to persist through a reboot, you may want to store it in either a local or remote VMFS/NFS volume.

I quickly verified that rsync was in functional, by rsyncing /etc directory in ESXi over to another host. I use the following command:

/tmp/rsync-static --compress --progress --stats -e dbclient -Rr /etc build-centos:/upload

Once the file transfer has completed, you should see the /etc directory replicated on the destination host.

You may have noticed in the command line we are specifying "dbclient", by default rsync will go over SSH but ESXi does not actually have the traditional ssh client that we are all used to. It actually uses dropbear which is tiny SSH server and client which is frequently used in embedded systems such as Busybox.

Since /bin/ssh path does not exists, rsync will fail unless you specify the dbclient to the -e parameter.

Alain also found that retrieving peer name may fail and the rsync code currently does not properly handle this failure and just exits. By looking at the clientname.c source code which is part of rsync, Alain noted that even the developers left a comment that states the error could probably be handled without exiting. The fix is to just comment out the rsynerr line which does not force the program to exit when hitting this problem and this can be found on line 171.

Once you have made the changes, you just need to follow the instructions above to compile your static rsync binary. This is not necessary required, but if you run into this issue, this is a quick hack that can help.

I would like to thank Alain for sharing this tidbit of information

31 thoughts on “How to compile a statically linked rsync binary for ESXi

  1. Hi!
    I did:
    Install a centos 3.9 (Is it the ok version?)
    Download a rsync 3.0.7.
    I did compile it, with yours instructions.
    I did copy then rsync executable to my esxi free 4.1.
    I did execute the rsync, and I did receive:
    Segmentation fault.
    I’m thinking the problem is whe don’t have the centos’s libc in the esxi 4.1:

    uidlist.o(.text+0xd2): In function gid_to_name':
    : Using 'getgrgid' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
    util.o(.text+0xc86): In function
    : Using ‘getgrnam’ in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
    util.o(.text+0xc27): In function name_to_uid':
    : Using 'getpwnam' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
    uidlist.o(.text+0x94): In function
    : Using ‘getpwuid’ in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
    socket.o(.text+0x413): In function `try_bind_local’:
    : Using ‘getaddrinfo’ in statically linked applications requires at runtime the shared libraries from the glibc version used for linking

    Do you have a solution for this?

    jorge infante
    rosario – santa fe – argentina

  2. which version of centos do you recommend using for an rsync binary in esxi 3.5? currently I receive this when running the rsync binary in esxi3.5.

    rsync error: syntax or usage error (code 1) at main.c(1408) [client=3.0.3]

  3. @Jesse,

    I don’t know, the version I used is listed in the blog post, I didn’t test with other versions of ESXi. Remember this is all unsupported, so it may just not work with older releases or even newer release for that matter. Good Luck

  4. Hi !
    My comment deals with a similar issue : using a NFS server binary inside ESXi.
    With the help of R Margar (, i can use directly the unfs binary from CentOS 5.5, inside ESXi 4.0. With Ghetto VCB, it’s very interesting to backup VM. But no READDIRPLUS makes this NFS server quite limited for live NFS Disk :-(.
    Did you already manage to create some kernel driver for ESXi, like an NFS server (which has READDIRPLUS procedure included) ?

  5. Hi William,

    I can confirm that on Centos 3/i386 I can compile (with warnings) and strip rsync-3.0.9 and it runs perfectly on ESXi 5.0 Update 1 | 15 MAR 2012 | Build 623860.

    Many thanks for a great post.

  6. Hi

    It seems that CentOS 3.9 is not supported anymore 🙂
    Luckily the Harvey Mudd College has a mirror 🙂
    The ISO can be found there:
    Also, you have to use that in the yum configuration too, because the CentOS site gives you a 404:

    perl -pi -e “s/centos\.org/” /etc/yum.conf

    Also load the GPG key:

    rpm –import

    I can confirm a working rsync 3.0.9 binary that seems to run OK on ESXi 5.1.0 build-799733.

    • or in /etc/yum.conf replace the source by ::

      name=CentOS-$releasever – Base

      #released updates
      name=CentOS-$releasever – Updates

      #packages used/produced in the build but not released
      name=CentOS-$releasever – Addons

      #additional packages that may be useful
      #name=CentOS-$releasever – Extras

      #additional packages that extend functionality of existing packages
      #name=CentOS-$releasever – Plus

      #packages in testing
      #name=CentOS-$releasever – Testing

      #between point release supported updates
      #name=CentOS-$releasever – Fasttrack

  7. Dick,
    Thank you VERY much for tracking down and sharing the Harvey Mudd hack. Very much appreciated 🙂

  8. where can I get rsync 3.0.9 binary for ESXi 5.1.0 build-799733.
    I do not succeed to compile on a ubuntu 12.04LTS

    Thank you

    uidlist.o: In function `gid_to_name’:
    uidlist.c:(.text+0x10a): warning: Using ‘getgrgid’ in statically linked applications requires at runtime the shared libraries from the glibc version used for linking

  9. Pulled rsync HEAD-20121003 that calls it self 3.1.0dev which didn’t have molniev’s patch, so it was applied. The rsynced sparse -flat file reported a different side on the nfs share, when it was rsynced back to esxi 5.1, it reported the correct size and booted. not much of a test, but feel free to try ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), statically linked, for GNU/Linux 2.2.5, stripped

    • thank you for the binary
      I have done few test

      time rsync –sparse –progress –stats -avz /vmfs/volumes/datavm216C/sauvegarde/alpi91/alpi91-2013-01-02_01-05-01/
      sending incremental file list
      alpi91-2013-01-05_01-05-01 -> /vmfs/volumes/datavm216C/sauvegarde/alpi91/alpi91-2013-01-05_01-05-01
      42,949,672,960 100% 3.95MB/s 2:52:39 (xfr#1, to-chk=4/7)
      542 100% 0.90kB/s 0:00:00 (xfr#2, to-chk=3/7)
      3,125 100% 4.72kB/s 0:00:00 (xfr#3, to-chk=2/7)
      21,474,836,480 100% 17.44MB/s 0:19:34 (xfr#4, to-chk=1/7)
      544 100% 1.01kB/s 0:00:00 (xfr#5, to-chk=0/7)

      Number of files: 7 (reg: 5, dir: 1, link: 1)
      Number of created files: 6 (reg: 5, link: 1)
      Number of deleted files: 0
      Number of regular files transferred: 5
      Total file size: 64,424,513,720 bytes
      Total transferred file size: 64,424,513,651 bytes
      Literal data: 64,424,513,651 bytes
      Matched data: 0 bytes
      File list size: 0
      File list generation time: 0.174 seconds
      File list transfer time: 0.000 seconds
      Total bytes sent: 15,645,990,678
      Total bytes received: 117

      sent 15,645,990,678 bytes received 117 bytes 1,356,098.88 bytes/sec
      total size is 64,424,513,720 speedup is 4.12
      real 3h 12m 17s
      user 1h 15m 48s
      sys 0m 0.00s

      + md5sum /vmfs/volumes/datavm216C/sauvegarde/alpi91/alpi91-2013-01-05_01-05-01/*

      It look find between 2
      VMkernel ordi216.cccp.local 5.1.0 #1 SMP Release build-799733 Aug 1 2012 20:03:00 x86_64 GNU/Linux

    • I try rsync binary on ESXi-5.5.0-1331820 but it does not work!

      rsync -a /C/fidit/ghettoVCB/conf/ ordi216.cccp.local:/C/tmp/
      ERROR: out of memory in map_ptr [sender]
      rsync error: error allocating core memory buffers (code 22) at util.c(119) [sender=3.1.0dev]
      md5sum /bin/rsync
      2a5e5a91de0cd00c8faa6f37d7172404 /bin/rsync

      Andrew cant yon send your binary please ?

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  11. William,

    Thanks for this well-written, very helpful post! I just used it to successfully compile rsync 3.1.0 for ESXi 4.1 on a CentOS 3.9/i386 VirtualBox VM, and have verified that I am now able to rsync to the host. Awesome!


    I used the process you described in your post, but made the following changes:

    – As described in Dick Visser’s comment, above, I used his Harvey Mudd College mod to get yum working with their CentOS 3.9 repo, and his reminder to import the CentOS 3 RPM GPG key from the URL he specified.

    – I had to use yum to install zlib-devel, in addition to gcc. This is probably because I installed a very basic pattern for CentOS 3.9.

    – Although not required, for ease of use, I created a utils directory on one of our datastores, used scp to copy the rsync-static binary to the utils directory, and then symlinked it to /usr/bin/rsync.



  12. (Using RobLogan’s download) rsync transfers work, except when a file name has dashes “-” in it. Trying to send such a file name yields this error:

    building file list … done
    ERROR: out of memory in map_ptr [generator]
    rsync: connection unexpectedly closed (30 bytes received so far) [sender]
    rsync error: error allocating core memory buffers (code 22) at /SourceCache/rsync/rsync-45/rsync/io.c(453) [sender=2.6.9]

    Remove the dashes, even change them to underscores “_”, or even spaces ” “, and it transfers fine.

  13. Configure and make commands for compiling rsync-3.1.1 on CentOS to run on ESXi 5.5 (possibly others, must test):

    ./configure –with-included-popt –with-included-zlib
    make LIBS=”-Wl,-static -lattr -lacl -Wl,-Bdynamic”

    The resultant binary is just ‘rsync’. This runs great on ESXi 5.5 and fixes the problem with DNS not resolving properly on the strictly statically linked versions. This is sort of a hybrid as it uses static versions of libacl and libattr but dynamic versions of glibc.

    Hope this helps anyone having trouble.

  14. So can I migrate a Live VM using this rsync method? I have a VPN server that needs to be moved to a different host. I want to do it while the server is online.


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