Process record of a failed migration of vmfstools from exsi

vmkfstools do ？

vmkfstools It's for management VMFS volume 、 Storage devices and virtual disks ESXi Shell Command one . have access to vmkfstools The command performs many storage operations . for example , You can create and manage on physical partitions VMFS data storage , Or operation VMFS or NFS A virtual disk file stored in a data store .（ Excerpt from vmware Official website ）

from EXSI System migration vmfstools Attempts to

pack vmfstools Program and dependency Library

EXSI System missing ldd command , You cannot directly query the dependent dynamic library , You can set LD_TRACE_LOADED_OBJECTS by 1 To get vmfstools Dependent dynamic libraries .

The content obtained is as follows ：

[root@localhost] vmkfstools
        libvmkfslib.so => /lib64/libvmkfslib.so (0x0000003f23cff000)
        libvmlibs.so => /lib64/libvmlibs.so (0x0000003f23f15000)
        libvmsnapshot.so => /lib64/libvmsnapshot.so (0x0000003f2444d000)
        libpollDefault.so => /lib64/libpollDefault.so (0x0000003f249be000)
        libpthread.so.0 => /lib64/libpthread.so.0 (0x0000003f24bc4000)
        libc.so.6 => /lib64/libc.so.6 (0x0000003f24de1000)
        librt.so.1 => /lib64/librt.so.1 (0x0000003f25190000)
        libcrypto.so.1.0.2 => /lib64/libcrypto.so.1.0.2 (0x0000003f25398000)
        libdl.so.2 => /lib64/libdl.so.2 (0x0000003f2585e000)
        libssl.so.1.0.2 => /lib64/libssl.so.1.0.2 (0x0000003f25a63000)
        libz.so.1 => /lib64/libz.so.1 (0x0000003f25cd7000)
        libgcc_s.so.1 => /lib64/libgcc_s.so.1 (0x0000003f25ef2000)
        /lib64/ld-linux-x86-64.so.2 (0x0000003ee3adc000)
        libtreestructs.so => /lib64/libtreestructs.so (0x0000003f26109000)

Directly package dependent libraries and executable programs , Execute... In the target environment chroot, The following errors are reported after execution ：

[root@localhost test]# chroot . /bin/vmkfstools
MD5 signature mismatch with running vmkernel built on _Unknown_ (my build date: Apr  3 2018 14:22:21)

The error message indicates ,vmkfstools Added verification for kernel version information .

strace track vmfstools Program execution

perform strace -f chroot . /bin/vmkfstools Get the following key information ：

uname({
    sys="Linux", node="sasl", ...})  = 0
access("/etc/vmware/hostd/mockupEsxHost.txt", F_OK) = -1 ENOENT (No such file or directory)
write(2, "MD5 signature mismatch with runn"..., 102MD5 signature mismatch with running vmkernel built on _Unknown_ (my build date: Apr  3 2018 14:22:21)

The information above indicates that , This procedure is through uname The system call is used to obtain the kernel version information , Then check . Can pass hook uname Library function to skip this check .

hook uname

#include <sys/utsname.h>
#include <string.h>

#define SYSNAME "VMkernel"
#define NODENAME "localhost"
#define RELEASE "6.7.0"
#define VERSION "#1 SMP Release build-8169922 Apr 3 2018 14:48:22"
#define MACHINE "x86_64"

int uname(struct utsname *name)
{
    
        if (!name)
                return 0;

        memcpy(name->sysname, SYSNAME, sizeof(SYSNAME));
        memcpy(name->nodename, NODENAME, sizeof(NODENAME));
        memcpy(name->release, RELEASE, sizeof(RELEASE));
        memcpy(name->version, VERSION, sizeof(VERSION));
        memcpy(name->machine, MACHINE, sizeof(MACHINE));

        return 0;
}

Execute the following command to compile the dynamic library ：

gcc -fPIC -shared uname.c -o uname.so

Verify that it works ：

[root@localhost ~]# LD_PRELOAD="/root/uname.so" uname -a
VMkernel localhost 6.7.0 #1 SMP Release build-8169922 Apr  3 2018 14:48:22 x86_64 x86_64 x86_64 GNU/Linux

The above output information indicates that it is effective .

chroot Environmental Science preload

Execute on chroot The following command line settings LD_PRELOAD Variable is , It is found that the program runs with an error . So in chroot Add... To your environment etc/ld.so.preload file , And set the file content to /lib64/uname.so. Later copy uname.so To chroot Environmental lib64 Directory .

Re execution chroot . /bin/vmkfstools, At this time, the following error is reported ：

[root@localhost test]#  chroot .   /bin/vmkfstools
Error during version check: Failed to get vmkernel version: 0xffffffda

The first kernel version Verification passed , The error message indicates that there are other verification methods in addition .

continue strace track

strace -f chroot . /bin/vmkfstools Get the following key information ：

syscall_1024(0x7ffcaf2fb6ac, 0, 0, 0x7ffcaf2fb300, 0xb, 0x3) = -1 (errno 38)
write(2, "Error during version check: Fail"..., 71Error during version check: Failed to get vmkernel version: 0xffffffda

This information indicates that ,vmkfstools The running kernel implements a system call for verifying the version , The kernel used in our system does not implement this system call , Then the test failed .

Confirm the return value 38 Indicates that the function is not implemented , Related definitions are as follows ：

#define ENOSYS 38 /* Function not implemented */

strace Compare the system call when executing this command on the native environment , I don't see any special projects , Feel a little strange , I have to give up first .