延迟和磁盘利用率会增加、例如ONTAP关闭
适用场景
任何具有Flash Cache的FAS型号(PAM或NVMe SSD)
问题描述
重新启动、关闭或升级后、ONTAP可能会报告延迟较长。系统会记录EMS日志"
extCache.warming "或"extCache.aggregate.invalidate "、例如：Sun Jul 26 09:41:38 -0500 [clus1-02: cf_giveback: extCache.aggregate.invalidate:info]: WAFL external cache: Started deferred invalidations for 2 aggregates. Sun Jul 26 09:41:38 -0500 [clus1-02: ec_exempt_worker_thread: extCache.aggregate.invalidate:info]: WAFL external cache: Starting deferred invalidation for aggregate in map slot 4. Sun Jul 26 09:41:38 -0500 [clus1-02: ec_exempt_worker_thread: extCache.aggregate.invalidate:info]: WAFL external cache: Starting deferred invalidation for aggregate in map slot 3. Sun Jul 26 09:41:41 -0500 [clus1-02: ec_exempt_worker_thread: extCache.aggregate.invalidate:info]: WAFL external cache: Completed invalidation for aggregate in map slot 4 in 3 seconds. Sun Jul 26 09:41:41 -0500 [clus1-02: ec_exempt_worker_thread: extCache.aggregate.invalidate:info]: WAFL external cache: Completed invalidation for aggregate in map slot 3 in 3 seconds. Sun Jul 26 09:41:41 -0500 [clus1-02: ec_exempt_worker_thread: extCache.aggregate.invalidate:info]: WAFL external cache: All pending deferred aggregate invalidations have completed. Total elapsed time: 3 seconds.
此外、在System Manager或Active IQ Unified Manager中可能会出现延迟。下面是一个系统的几个示例、该系统于7月26日进行了ONTAP升级、您可以在7月27日午夜看到延迟略高：
ActiveIQ显示"聚合操作"集群组件中的延迟增加、或者由于从Flash Cache读取的百分比较低、因此从硬盘驱动器的延迟基本增加。
