wikiMegaRAID controllers
Broadcom offers with MegaRAID controllers a wide range of hardware RAID controllers for the configuration of RAID alliances. This article shows current controller generations and which mechanisms are used for protecting the cache of these controllers.
MegaRAID controller generations
This table shows the latest MegaRAID controller generations in an overview:
| controller generations | internal ports | external ports | PCIe lanes | cache | cache protection |
|---|---|---|---|---|---|
| MegaRAID 9600 Series Tri-Mode Storage Adapters | up to 24 | - | up to 16 PCIe 4.0 |
|
CacheVault |
| MegaRAID 9500 Series Tri-Mode Storage Adapters | up to 16 | up to 8 | 8 PCIe 4.0 |
|
CacheVault |
| MegaRAID 9400 Series Tri-Mode Storage Adapters | 8 PCIe 3.1 |
|
CacheVault | ||
| MegaRAID 12Gbs RAID Controller (9300 series) | up to 28 | 8 PCIe 3.0 |
|
CacheVault | |
| MegaRAID 6Gbs RAID Controller (9200 series) | up to 24 | 1 to 8 PCIe 2.0 |
|
CacheVault or BBU |
MegaRAID controllers in a server
An example of a server configuration with MegaRAID cotrollers can be found in Product not available anymore.
Cache protection
MegaRAID controllers offer an integrated cache to accelerate write accesses. To ensure that the contents of the cache are retained in the event of a power failure, it can be protected with LSI CacheVault.
Further information on the cache settings can be found in the following article: RAID Controller and Hard Disk Cache Settings.
CacheVault
No battery is used for cache protection with CacheVault. Instead, in the event of a power failure, a capacitor briefly supplies enough energy to write the contents of the volatile cache to non-volatile flash memory. The contents of the cache are thus retained in the flash memory, regardless of how long the power failure lasts. In addition, this solution is maintenance-free, as there are no batteries that need to be replaced at regular intervals.
Battery Backup Unit
With cache protection using a battery backup unit (BBU), a rechargeable battery retains the contents of the cache. Depending on the capacity of the battery and its current charge level, the contents of the cache can be retained for up to 72 hours. If the power failure lasts longer than this, the contents of the cache will be lost.
BBUs must be maintained regularly. Information on this can be found in the Battery Backup Unit (BBU/BBM) Maintenance for RAID Controllers article.
More information
- Broadcom RAID Controller Cards (www.broadcom.com)
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Author: Werner Fischer Werner Fischer, working in the Knowledge Transfer team at Thomas-Krenn, completed his studies of Computer and Media Security at FH Hagenberg in Austria. He is a regular speaker at many conferences like LinuxTag, OSMC, OSDC, LinuxCon, and author for various IT magazines. In his spare time he enjoys playing the piano and training for a good result at the annual Linz marathon relay.
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Translator: Alina Ranzinger Alina has been working at Thomas-Krenn.AG since 2024. After her training as multilingual business assistant, she got her job as assistant of the Product Management and is responsible for the translation of texts and for the organisation of the department.
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