How to Fix Slow EFS Performance During Peak Hours for SAP

Quick Answer

EFS performance in its default bursting throughput mode is tied to the size of the file system and a pool of burst credits that get consumed faster than they accumulate under sustained heavy demand, which matches the pattern described here - file operations slow down specifically during peak hours when usage is highest. Enabling Provisioned Throughput mode decouples throughput from file system size and burst credit balance entirely, letting you set a fixed, guaranteed throughput level that can absorb sustained peak-hour demand. That directly resolves the described symptom because the bottleneck isn't storage capacity or the number of servers accessing the share, it's the throughput ceiling the file system is allowed to sustain. The other approaches target the wrong layer: EBS with Multi-Attach caps out at a small number of attached instances and isn't designed as a general-purpose shared file system for something like SAP transport files; Amazon S3 isn't a POSIX file system at all, so bolting on something like S3FS introduces compatibility and latency problems rather than solving them; and simply adding more EC2 instances doesn't change EFS's throughput ceiling, since that ceiling is a property of the file system itself, not the number of clients connected to it. Whenever a shared EFS mount shows slow performance specifically tied to peak usage, look for a throughput-mode answer rather than a compute or client-count change.