Forum Discussion
ushan
Altocumulus
AltocumulusBIG IQ DCD
If I have 3 DCD node in a cluster how does the DCD nodes store the log? Will all three nodes store the logs partially? Or, only one node stores the log initally and replicate it to other nodes? Ho...
David_Larsen
Employee
EmployeeMy understanding from attempts to recover a failed disk on a DCD is that each node gets portions of the logs along with the needs to rebuild missing bits. So think of it like a disk RAID set. DCD1 gets first bit, DCD2 gets second bit, DCD3 gets third bit, then DCD1 gets the check bit. And it cycles through each in Databasse Shards and collectively they have all the data and on a failure they can recover the data. This is also why 3 or more DCD are necessary if you want to be able to recover from a DCD failure.
ushanHi David_Larsen My DCD is a VM and not a physical appliance. And RAID is maintained by my physical server (Dell).
Also I don't have enough resource in my physical server to install all three DCD nodes.
Since the disk redundancy is maintained by my physical server will I still need to install all three DCD nodes or only one or two will be enough.