Hi, Patrol Read is designed for SAS and SATA Disks only and is not recommended for SSD.   KB Article [URL]   Stoping Patrol Read is explained in these manuals for example: [URL]   [URL]   Did you have any further questions?   Regards Martin      
Hello Dell Experts,   We noticed a significant slowdown in IO performance on one of our database servers during the weekly run of Patrol Read: Dell PowerEdge R640 with PERC H740P Mini and 8x SAS SSDs (KPM5XRUG3T84) as RAID5 (latest firmware installed).   1. Is it recommended to run Patrol Read on SSDs? There's a setting "includessds= ". Any reason this can be turned off specifically for SSDs?    2. The setting "maxconcurrentpd" defaults to 64 (max number of physical disks that can be patrol read at a single time). Would setting the value to 1 help mitigate the negative IO impact?   3. Are there further options to tune Patrol Read (similar to "ccrate" of the consistency check feature)?   Thank you!
Patrol Read / Degraded IO throughput