我正在阅读以下指南http://www.postgresonline.com/journal/archives/329-An-almost-idiots-guide-to-install-PostgreSQL-9.3，-PostGIS-2.1-和-pgRouting-with-Yum.html（此链接来自http://postgis.net/install)。命令yum install postgis2_93给出以下错误：
Error: Package: gdal-libs-1.9.2-6.rhel6.x86_64 (pgdg93)
Requires: libhdf5.so.6()(64bit)
Error: Package: gdal-libs-1.9.2-6.rhel6.x86_64 (pgdg93)
Requires: libdapserver.so.7()(64bit)
Error: Package: gdal-libs-1.9.2-6.rhel6.x86_64 (pgdg93)
Requires: libCharLS.so.1()(64bit)
Error: Package: postgis2_93-2.1.3-1.rhel6.x86_64 (pgdg93)
Requires: libjson.so.0()(64bit)
Error: Package: gdal-libs-1.9.2-6.rhel6.x86_64 (pgdg93)
Requires: libgta.so.0()(64bit)
Error: Package: gdal-libs-1.9.2-6.rhel6.x86_64 (pgdg93)
Requires: libspatialite.so.2()(64bit)
Error: Package: gdal-libs-1.9.2-6.rhel6.x86_64 (pgdg93)
Requires: libcfitsio.so.0()(64bit)
Error: Package: postgis2_93-2.1.3-1.rhel6.x86_64 (pgdg93)
Requires: json-c
Error: Package: postgis2_93-2.1.3-1.rhel6.x86_64 (pgdg93)
Requires: hdf5
Error: Package: armadillo-4.300.0-1.rhel6.x86_64 (pgdg93)
Requires: libhdf5.so.6()(64bit)
Error: Package: gdal-libs-1.9.2-6.rhel6.x86_64 (pgdg93)
Requires: libnetcdf.so.6()(64bit)
Error: Package: gdal-libs-1.9.2-6.rhel6.x86_64 (pgdg93)
Requires: libdapclient.so.3()(64bit)
Error: Package: armadillo-4.300.0-1.rhel6.x86_64 (pgdg93)
Requires: libarpack.so.2()(64bit)
Error: Package: gdal-libs-1.9.2-6.rhel6.x86_64 (pgdg93)
Requires: libfreexl.so.1()(64bit)
Error: Package: gdal-libs-1.9.2-6.rhel6.x86_64 (pgdg93)
Requires: libdap.so.11()(64bit)
他们是意料之中的事。然后我做以下操作（根据指南）：
sudo rpm -ivh http://dl.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-8.noarch.rpm
CCD_ 2给出以下结果：
http://mirror.logol.ru/epel/6/x86_64/repodata/9fdd4609f219b3ec5cfa5408ab03b84b2bce97ab6de268b890577ee86b998618-primary.sqlite.bz2: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://mirror.awanti.com/epel/6/x86_64/repodata/9fdd4609f219b3ec5cfa5408ab03b84b2bce97ab6de268b890577ee86b998618-primary.sqlite.bz2: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://ftp.fi.muni.cz/pub/linux/fedora/epel/6/x86_64/repodata/9fdd4609f219b3ec5cfa5408ab03b84b2bce97ab6de268b890577ee86b998618-primary.sqlite.bz2: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://ftp.linux.cz/pub/linux/fedora/epel/6/x86_64/repodata/9fdd4609f219b3ec5cfa5408ab03b84b2bce97ab6de268b890577ee86b998618-primary.sqlite.bz2: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://centos.kiewel-online.ch/epel/6/x86_64/repodata/9fdd4609f219b3ec5cfa5408ab03b84b2bce97ab6de268b890577ee86b998618-primary.sqlite.bz2: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://ftp.uni-kl.de/pub/linux/fedora-epel/6/x86_64/repodata/9fdd4609f219b3ec5cfa5408ab03b84b2bce97ab6de268b890577ee86b998618-primary.sqlite.bz2: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://mirror.switch.ch/ftp/mirror/epel/6/x86_64/repodata/9fdd4609f219b3ec5cfa5408ab03b84b2bce97ab6de268b890577ee86b998618-primary.sqlite.bz2: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://www.mirrorservice.org/sites/dl.fedoraproject.org/pub/epel/6/x86_64/repodata/9fdd4609f219b3ec5cfa5408ab03b84b2bce97ab6de268b890577ee86b998618-primary.sqlite.bz2: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
...
CCD_ 3和CCD_。我也尝试过使用EPEL7.1，但我也出现了同样的错误。我在哪里可以买到这些包裹？
切换到/etc/yum.repos.d/epel.repo:中的baseurl
baseurl=http://download.fedoraproject.org/pub/epel/6/$basearch
#mirrorlist=https://mirrors.fedoraproject.org/metalink?repo=epel-6&arch=$basearch
修复程序将在接下来的几个小时内传播到镜像。
稍后一定要再次切换到镜像列表，这样我们就不会所有人都抨击分配给download.fedoraproject.org 的主机
它对我有效。
yum install https://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm
https://unix.stackexchange.com/a/598051/522973