Locating issues:  Although IBM FlashSystem 9100 raises error messages, events might  not be caused by IBM FlashSystem 9100. Some issues are introduced by the storage  subsystems or the SAN. If the problem is caused by IBM FlashSystem 9100 and you are unable to fix it by using the  Recommended Action feature or the event log, collect the IIBM FlashSystem 9100 support  package as described in 10.4.1, “Collecting data from IBM FlashSystem 9100” on page 369.  To identify and fix other issues outside of IBM FlashSystem 9100, consider the guidance in  the other sections in this chapter that are not related to IBM FlashSystem 9100. When IBM FlashSystem 9100 detects a failed NVMe drive or optional external attached flash  drive, it automatically generates an error in the  Events  panel. To replace the failed drive,  always run  Fix Procedure  for this event in  Monitoring  Events  panel. The  Fix Procedure  will help you to identify the enclosure and slot where the bad drive is  located, and will guide you to the correct steps to follow in order to replace it. When a flash  drive fails, it is removed from the array. If a suitable spare drive is available, it is taken into the  array and the rebuild process starts on this drive. After the failed flash drive is replaced and the system detects the replacement, it reconfigures  the new drive as spare. So, the failed flash drive is removed from the configuration, and the  new drive is then used to fulfill the array membership goals of the system. Apart from hardware-related situations, problems can exist in such areas as the operating  system or the software that is used on the host. These problems normally are handled by the  host administrator or the service provider of the host system. However, the multipathing driver  that is installed on the host and its features can help to determine possible issues.  Example 10-9 shows a volume path issue reported by SDD output on the host by using the  datapath query adapter  and  datapath query device  commands. The adapter in degraded  state means that specific HBA on the server side can’t reach all the nodes in the I/O group  which the volumes are associated. Also we can notice in the  datapath query device command output that each device (or volume) has only three paths, when it is expected to  have four paths. Example 10-9 SDD output on a host with faulty paths  C:\Program Files\IBM\SDDDSM> datapath query adapter Active Adapters :2 Adpt# Name Interface State Mode Select Errors Paths Active 0 Scsi Port2 Bus0 FC DEGRAD ACTIVE 1860589 293 4 4 1 Scsi Port3 Bus0 FC NORMAL ACTIVE 1979793 259 8 8 C:\Program Files\IBM\SDDDSM> datapath query device Total Devices : 8 DEV#: 0 DEVICE NAME: Disk2 Part0 TYPE: 2145 POLICY: LEAST I/O AND WEIGHT SERIAL: 600507680C838020E80000000000001B Reserved: No LUN SIZE: 5.0GB Replacing a failed flash drive 10.5.2 Solving host problems 376  IBM FlashSystem 9200 and 9100 Best Practices and Performance Guidelines