# Storage Config

## Learn how to configure storage in TiKV.

This document describes the configuration parameters related to storage.

### scheduler-concurrency

• A built-in memory lock mechanism to prevent simultaneous operations on a key. Each key has a hash in a different slot.
• Default value: 2048000
• Minimum value: 1

### scheduler-worker-pool-size

• The number of scheduler threads, mainly used for checking transaction consistency before data writing
• Default value: 4
• Minimum value: 1

### scheduler-pending-write-threshold

• The maximum size of the write queue. A Server Is Busy error is returned for a new write to TiKV when this value is exceeded.
• Default value: 100MB
• Unit: MB|GB

### reserve-space

• The size of the temporary file that preoccupies the extra space when TiKV is started. The name of temporary file is space_placeholder_file, located in the storage.data-dir directory. When TiKV runs out of disk space and cannot be started normally, you can delete this file as an emergency intervention and set reserve-space to 0MB.
• Default value: 2GB
• Unite: MB|GB