If a drive fails to format, it should go offline with its format marked as degraded and will  require a manual format to bring it back online. The CLI scenario is shown in Example 3-1. Example 3-1 Manual FCM format IBM_FlashSystem:FS9100-ITSO:superuser>lsdrive id status error_sequence_number use tech_type .... .... 13 offline 118 candidate tier0_flash .... IBM_FlashSystem:FS9100-ITSO:superuser>chdrive -task format 13 IBM_FlashSystem:FS9100-ITSO:superuser> An FCM is expected to format in under 70 seconds. GLYPH<SM590000> When a drive is replaced in the same slot, the system tries to take the drive as a  replacement for the array member. The drive will have to format first, so this might take  some time for an FCM. GLYPH<SM590000> For NVMe drives and FCMs, formatting the drive completes a cryptographic erase of the  drive. GLYPH<SM590000> The FlashSystem 9100 system GUI (as shown in Figure 3-1) and CLI (as shown in  Example 3-2) allows you to monitor effective and physical capacity for each FCM. If the drive was previously encrypted in another array, it will come up as failed since this  system won’t have the required keys. The drive must be manually formatted to make it a  candidate.  Figure 3-1 FCM capacity monitoring with GUI Example 3-2 FCM capacity monitoring with CLI IBM_FlashSystem:FS9100-ITSO:superuser>lsdrive 0 id 0 ... tech_type tier0_flash capacity 20.0TB ... compressed yes physical_capacity 4.36TB physical_used_capacity 8.97GB effective_used_capacity 9.15GB Both examples show same 4.8 TB FCM with maximum effective capacity of 20 TiB (or  21.99 TB). Chapter 3. Drives and arrays  45