[Discussion] Hypercache question

[TMbuddy]

The changes made to Hyper cache in TOS 6.0.694 only involve the calculation of cache capacity, and are not related to cache modes.
There have always been only two cache modes.

[sianderson]

The changes made to Hyper cache in TOS 6.0.694 only involve the calculation of cache capacity, and are not related to cache modes.
There have always been only two cache modes.

i assume you mean 3 not 2?

"Hyper Cache can provide up to 3 cache modes to choose from to suit different usage needs"

Mode definitions:
1. Read-write mode
Description: This mode provides cache acceleration for reading and writing. The data will be written to the SSD cache first, and then written to the hard disk later; the disadvantage of the read-write mode is that it is not safe enough. Once the SSD fails or the power is cut off midway, the data may be lost; if you need to improve the read-write mode For security, multiple SSDs can be used to form a RAID 1 or RAID 5 array to provide redundancy for caching SSDs, which not only increases the capacity of the cache, but also avoids the risk of data loss caused by SSD failure. The read-write mode is suitable for users who have high requirements for cache read and write performance.

2. Balance mode
Description: This mode provides preloaded read cache acceleration. Data will be written to the SSD cache and hard disk at the same time, the data writing speed will be reduced to a certain extent, but the reading speed can be increased. Balanced mode can avoid the risk of SSD failure or loss caused by midway power failure; in this mode, the read and write speed of the cache can be improved by using 2 SSDs to form a RAID 0 array. Balanced mode is suitable for users who do not require high write cache performance but high read cache performance.

3. Read-only mode
Note: This mode only provides read cache acceleration. The data will be written directly to the hard disk instead of the cache, and the failure of the SSD will not affect the security of the data; in the read-only mode, if two SSDs are used to form a RAID 0 array, the read speed of the cache can be improved. The read-only mode is suitable for users who have high requirements for data security but not high requirements for cache write performance.

unless you are contradicting TMRoy?

[luismartin]

With las 6.x updates there are only 2 modes.
And I have 16GB of RAM but I still say that I don't notice any difference between having Hypercache in Balanced mode or not having it activated, that's why I forget about that feature which in my case is useless (maybe it causes some problem)

[TMroy]

Multiple factors can prevent you from experiencing HyperCache's performance benefits. Firstly, your network interface bandwidth acts as a bottleneck, capping storage throughput. When your storage media performance exceeds the network port's bandwidth, caching cannot deliver observable improvements regardless of configuration. Secondly, during sustained large-file sequential I/O operations, the inherently low cache hit rate in linear data patterns similarly fails to yield perceptible gains. A fundamental understanding of caching mechanisms is prerequisite to analyzing performance under your specific workload conditions.