以下摘自Xen邮件列表：
Hi all,
Since I am a newbie of Xen, this may be a dumb question. On my SuSE Xen, I find the following 4 “Xen” files:
-rw-r–r– 1 root rootÂÂÂ881967 Oct 27 05:46 xen-4.5.110-1.gz
-rw-r–r– 1 root root 16673080 Oct 27 05:46 xen-syms-4.5.110-1
-rw-r–r– 1 root rootÂÂÂ893428 Oct 27 05:45 xen-dbg-4.5.110-1.gz
-rw-r–r– 1 root root 16124144 Oct 27 05:45 xen-syms-dbg-4.5.110-1Could anyone give a detailed explanation of the functions and differences about the 4 files?
TL;DR: Use xen-04.5.1_1-1.gz unless someone asks you to do otherwise or you are tracking down a bug.
xen.gz is the main/regular/normal release build of the Xen binary (e.g. the thing which you can boot). This is the thing you would boot on a regular production Xen system.
xen-syms.gz is the unstripped version of xen.gz, i.e. with all the ELF debug information present. You can e.g. run gdb on it to disassemble things if you are tracking down a bug. This image is not bootable.
The -dbg variants are not something which upstream produces, but I would assume that they are build with the debug=y, which means they will contain extra ASSERT statements and other things which aid debugging possibly at the expense of performance. Release builds (xen.gz et al) are build with debug=n. Like the release builds the xen-*-dbg ones come in the bootable (xen-dbg.gz) and xen-syms-dbg.gz variants, with the same distinction (the former is bootable, the latter is for running gdb on)
概括一下，xen文件是可以bootable的，也是用来启动xen系统的可执行文件。xen-sym是xen的保留所有调试信息的的版本，不可以bootable，仅用于调试功能。xen-*-dbg则是xen和xen-sym对应的加了很多调试代码的版本。