For any filesystem devices, it will be better if you turn OFF journalining, EXT4 performance will suffer if journaling it turned ON. Performance wise plain Unix raw devices always perform better than other type in same environment. On RedHat use tune2fs command to turn off journaling for ext[34] file systems
tune2fs -O ^has_journal DEVICE_ON_WHICH_FILE_SYSTEM_EXISTS
Then need to run fsck
e2fsck DEVICE_ON_WHICH_FILE_SYSTEM_EXISTS
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Regards
Shashi