CacheCade is used to improve random read performance of the Hard Disk Drive (HDD) based Virtual Disks. A solid-state drive (SSD) is a data storage device that uses solid-state memory to store persistent data. SSDs significantly increase the I/O performance (IOPS) and/or write speed in Mbps from a storage device. With Dell Storage Controllers, you can create a CacheCade using SSDs. The CacheCade is then used for better performance of the storage I/O operations. Use either Serial Attached SCSI (SAS) or Serial Advanced Technology Attachment (SATA)SSDs to create a CacheCade.
Create a CacheCade with SSDs in the following scenarios:
- Maximum application performance—Create a CacheCade using SSDs to achieve higher performance without wasted capacity.
- Maximum application performance and higher capacity—Create a CacheCade using SSDs to balance the capacity of the CacheCade with high performance SSDs.
- Higher capacity—If you do not have empty slots for additional HDDs, use SSDs and create a CacheCade. This reduces the number of HDDs required and increases application performance.
The CacheCade feature has the following restrictions:
- Only SSDs with the proper Dell identifiers can be used to create a CacheCade.
- If you create a CacheCade using SSDs, the SSD properties are still retained. At a later point of time, you can use the SSD to create virtual disks.
- A CacheCade can contain either SAS drives or SATA drives but not both.
- Each SSD in the CacheCade does not have to be of the same size. The CacheCade size is automatically calculated as follows:
CacheCade size =capacity of the smallest SSD * the number of SSDs
The unused portion of SSD is wasted and can not be used as an additional CacheCade or an SSD-based virtual disk.
- The total amount of cache pool with a CacheCade is 512 GB. If you create a CacheCade which is larger than 512 GB, the storage controller still uses only 512 GB.
- The CacheCade is supported only on Dell PERC H700 and H800 controllers with 1 GB NVRAM and firmware version 7.2 or later.
- In a storage enclosure, the total number of logical devices including virtual disks and CacheCade(s) cannot exceed 64.
