Managing a Read/Write Cache

BrickStor uses Adaptive Replacement Cache (ARC) for caching frequently accessed data into the system’s memory (RAM); so as memory increases, so will the caching efficiency.

Add Read Cache

Insert a read performance-focused SSD into BrickStor system and follow the instructions below to elect it as a Read Cache device for a given pool. Read more about Read Cache here.

To add a read cache to an existing pool:

  1. Navigate to the desired pool.

  2. Click Add read cache in the Available Drives Detected panel.

    add read cache flyout

  3. Select a Drive Type.

  4. Enter a Drive Count.

  5. Click Add read cache to confirm.

Add Write Cache Mirror

Insert two write performance-focused SSD into BrickStor system and follow the instructions below to elect it as mirrored (RAID1) Write Cache device for a given pool.

RackTop recommends using mirrored/RAID1 write cache devices as a means of preventing the loss of a journal device, which has potential availability impact.

ZFS uses RAM as write cache to improve performance and is referred to as the ZFS Intent Log (ZIL). It temporarily holds synchronous writes before writing them to disk. Enhance write performance further by adding an SSD as a secondary log (SLOG) device. Read more about Write Cache here.

To add a write cache to an existing pool:

  1. Navigate to the desired pool.

  2. Click Add write cache mirror in the Available Drives Detected panel.

    add write cache mirror flyout

  3. Select a Drive Type.

  4. Enter a VDEV Count.

  5. Enter the number of Drives per VDEV.

  6. Click Add write cache mirror to confirm.