Saturday, December 17, 2005
Ask the Zerowait Engineer...
We received the following question from a customer.....
Your web site is saying some people reported 30% overhead with ZCS checksums. Performance-wise, should we opt for FC9s shelves with BCS drives?
If you are running your filers at 80-90% capacity then you might benefit from the extra speed of the BCS drives. If your filers are not maxed out then the extra benefit is minimal. The real advantage to the FC9 and DS14 shelves is not their ability to use BCS drives, but rather their ability to run large drives. The FC8 shelf power supplies aren't rated to handle the larger drives. Also the FC9 and DS14 shelves can be multi-pathed for redundancy. Generally, most people would not upgrade or change to BCS drives for the possible performance increase unless the filer is near capacity. If you see a "value add" in the other advantages, however, then it might be worth looking into.
The BCS are faster due to the ability to write the checksum into the extra blocks in the format. This saves time having to pull the checksum from the disk.
Is your filer's data worth $5.00 a day? If so, you may want to call Zerowait.