Dell EMC VxFlex Ready Node, User Manual

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Task Command
l
scli --set_rmcache_usage --
protection_domain_name <domain NAME> --
storage_pool_name <pool NAME> --use_rmcache
[--dont_use_rmcache]
l
scli --enable_sds_rmcache [--
disable_sds_rmcache] --sds_name <NAME>
Note: Using this command would be required for every
SDS in the cluster.
To increase the amount of
Read RAM cache Run the following command:
scli --set_sds_rmcache_size ((--sds_id <ID> | --
sds_name <NAME> | --sds_ip <IP> [--sds_port
<PORT>]) | (--protection_domain_id <ID> | --
protection_domain_name <NAME>)) --
rmcache_size_mb <SIZE> [--i_am_sure]
Where --rmcache_size_mb is the size of rmcache in MB, and
the range is between 128MB-300GB.
It is important to ensure that Read RAM cache is enabled at all
levels (PD, SP, and SDS). When rmcache is properly enabled,
query output will look like this:
Read Flash Cache settings for SDS
Read Flash Cache is available from version 2.x and later. This feature is a Read Cache
used to increase read performance and buffers writes to increase the performance of
Read-after-Write I/Os. It allows users to create and configure an "RFcache" device
for any SSD or Flash card. VxFlex OS will cache user data depending on the mode
selected. This feature can greatly improve performance for specific workloads. The
RFcache device is also referred to as an accelerated device.
To create an RFcache device and configure it, use the following steps:
1. Create an RFcache device (Recommendation: create 1 device per SDS).
scli --add_sds_rfcache_device --sds_name <NAME> --
rfcache_device_path <device_path> --rfcache_device_name
<RFcache device NAME>
VxFlex OS performance fine-tuning
116 Dell EMC VxFlex Ready Node AMS User Guide