nscd.conf (5) - 名称服务缓存守护程序配置文件
文件 /etc/nscd.conf 在启动时从 nscd - 名称服务缓存守护程序 读取。每行指定一个属性和一个值，或者指定一个属性、服务和一个值。字段由空格或制表符分隔。#（数字符号）表示注释的开头; nscd 不会解释后面的字符，直到行尾。
有效的服务是 passwd, group, hosts, services 或者 netgroup.
**logfile** _debug-file-name_
指定应将调试信息写入的文件的名称
**debug-level** _value_
设置所需的调试级别。默认值为 0
**threads** _number_
这是启动等待请求的线程数。将始终至少创建五个线程
**max-threads** _number_
指定最大线程数。默认值为 32
**server-user** _user_
如果设置了此选项，nscd 将以此用户身份运行，而不是以 root 用户身份运行。如果为每个用户使用单独的缓存（-S 参数），则忽略此选项。
**stat-user** _user_
指定允许请求统计信息的用户
**reload-count** unlimited | _number_
限制缓存条目在被删除之前未被使用而重新加载的次数。默认值为 5
**paranoia** _<yes|no>_
启用偏执模式会导致 nscd 定期重新启动。默认值为 no
**restart-interval** _time_
如果通过启用偏执狂模式启用了定期重新启动，则将重新启动间隔设置为_时间_秒。默认值为 3600
**enable-cache** _service <yes|no>_
启用或禁用指定的_服务_缓存。默认值为 no.
**positive-time-to-live** _service value_
为_服务的_指定缓存中的正条目（成功的查询）设置 TTL（Time-To-Live）。_值_以秒为单位。值越大，缓存命中率越高，平均响应时间越短，但缓存一致性问题越大
**negative-time-to-live** _service value_
为_服务的_指定缓存中的负条目（不成功的查询）设置 TTL（生存时间）。_值_以秒为单位。如果 UID（用户 ID）拥有的多个文件不在系统数据库中（例如，将 Linux 内核源代码解压缩为 root），则可以显著提高性能;应保持较小以减少缓存一致性问题。
**suggested-size** _service value_
这是内部哈希表的大小，_值_应保持为素数以获得最佳效率。默认值为 211
**check-files** _service <yes|no>_
启用或禁用检查属于指定_服务_的文件是否有更改。这些文件是 /etc/passwd、/etc/group、/etc/hosts、/etc/services 和 /etc/netgroup。默认值为 yes
**persistent** _service <yes|no>_
保留缓存的内容，以便在服务器重新启动时_提供服务_;在设置偏执模式时很有用。默认值为 no
**shared** _service <yes|no>_
用于_服务的_ nscd 数据库的内存映射与客户端共享，以便它们可以直接在其中进行搜索，而不必在每次执行查找时都通过套接字询问守护程序。默认值为 no
**max-db-size** _service bytes_
_服务的_数据库文件允许的最大大小（以字节为单位）。默认值为 33554432
**auto-propagate** _service <yes|no>_
如果为 passwd 或_组_服务设置为 no，则不会将 .byname 请求添加到 passwd.byuid 或 group.bygid 缓存中。这可以帮助表包含同一 ID 的多个记录。默认值为 yes。此选项仅对服务 passwd 和_组_有效
文件内容
#
# /etc/nscd.conf
#
# An example Name Service Cache config file. This file is needed by nscd.
#
# WARNING: Running nscd with a secondary caching service like sssd may lead to
# unexpected behaviour, especially with how long entries are cached.
#
# Legal entries are:
#
# logfile <file>
# debug-level <level>
# threads <initial #threads to use>
# max-threads <maximum #threads to use>
# server-user <user to run server as instead of root>
# server-user is ignored if nscd is started with -S parameters
# stat-user <user who is allowed to request statistics>
# reload-count unlimited|<number>
# paranoia <yes|no>
# restart-interval <time in seconds>
#
# enable-cache <service> <yes|no>
# positive-time-to-live <service> <time in seconds>
# negative-time-to-live <service> <time in seconds>
# suggested-size <service> <prime number>
# check-files <service> <yes|no>
# persistent <service> <yes|no>
#
# shared <service> <yes|no>
# NOTE: Setting 'shared' to a value of 'yes' will accelerate the lookup
# with the help of the client, but these lookups will not be
# counted as cache hits i.e. 'nscd -g' may show '0%'.
#
# max-db-size <service> <number bytes>
# auto-propagate <service> <yes|no>
#
# Currently supported cache names (services): passwd, group, hosts, services
#
# logfile /var/log/nscd.log
# threads 4
# max-threads 32
server-user nscd
# stat-user somebody
debug-level 0
# reload-count 5
paranoia no
# restart-interval 3600
enable-cache passwd yes
positive-time-to-live passwd 600
negative-time-to-live passwd 20
suggested-size passwd 211
check-files passwd yes
persistent passwd yes
shared passwd yes
max-db-size passwd 33554432
auto-propagate passwd yes
enable-cache group yes
positive-time-to-live group 3600
negative-time-to-live group 60
suggested-size group 211
check-files group yes
persistent group yes
shared group yes
max-db-size group 33554432
auto-propagate group yes
enable-cache hosts yes
positive-time-to-live hosts 3600
negative-time-to-live hosts 20
suggested-size hosts 211
check-files hosts yes
persistent hosts yes
shared hosts yes
max-db-size hosts 33554432
enable-cache services yes
positive-time-to-live services 28800
negative-time-to-live services 20
suggested-size services 211
check-files services yes
persistent services yes
shared services yes
max-db-size services 33554432
enable-cache netgroup yes
positive-time-to-live netgroup 28800
negative-time-to-live netgroup 20
suggested-size netgroup 211
check-files netgroup yes
persistent netgroup yes
shared netgroup yes
max-db-size netgroup 33554432#
# /etc/nscd.conf
#
# An example Name Service Cache config file. This file is needed by nscd.
#
# WARNING: Running nscd with a secondary caching service like sssd may lead to
# unexpected behaviour, especially with how long entries are cached.
#
# Legal entries are:
#
# logfile <file>
# debug-level <level>
# threads <initial #threads to use>
# max-threads <maximum #threads to use>
# server-user <user to run server as instead of root>
# server-user is ignored if nscd is started with -S parameters
# stat-user <user who is allowed to request statistics>
# reload-count unlimited|<number>
# paranoia <yes|no>
# restart-interval <time in seconds>
#
# enable-cache <service> <yes|no>
# positive-time-to-live <service> <time in seconds>
# negative-time-to-live <service> <time in seconds>
# suggested-size <service> <prime number>
# check-files <service> <yes|no>
# persistent <service> <yes|no>
#
# shared <service> <yes|no>
# NOTE: Setting 'shared' to a value of 'yes' will accelerate the lookup
# with the help of the client, but these lookups will not be
# counted as cache hits i.e. 'nscd -g' may show '0%'.
#
# max-db-size <service> <number bytes>
# auto-propagate <service> <yes|no>
#
# Currently supported cache names (services): passwd, group, hosts, services
#
# logfile /var/log/nscd.log
# threads 4
# max-threads 32
server-user nscd
# stat-user somebody
debug-level 0
# reload-count 5
paranoia no
# restart-interval 3600
enable-cache passwd yes
positive-time-to-live passwd 600
negative-time-to-live passwd 20
suggested-size passwd 211
check-files passwd yes
persistent passwd yes
shared passwd yes
max-db-size passwd 33554432
auto-propagate passwd yes
enable-cache group yes
positive-time-to-live group 3600
negative-time-to-live group 60
suggested-size group 211
check-files group yes
persistent group yes
shared group yes
max-db-size group 33554432
auto-propagate group yes
enable-cache hosts yes
positive-time-to-live hosts 3600
negative-time-to-live hosts 20
suggested-size hosts 211
check-files hosts yes
persistent hosts yes
shared hosts yes
max-db-size hosts 33554432
enable-cache services yes
positive-time-to-live services 28800
negative-time-to-live services 20
suggested-size services 211
check-files services yes
persistent services yes
shared services yes
max-db-size services 33554432
enable-cache netgroup yes
positive-time-to-live netgroup 28800
negative-time-to-live netgroup 20
suggested-size netgroup 211
check-files netgroup yes
persistent netgroup yes
shared netgroup yes
max-db-size netgroup 33554432