Brocade HBA - Stream I/O Performance - Page 4
Texas Memory Systems RamSan 400
- (4) dual-port 4Gbps HBAs
- 32GB RAM
Xiotech Emprise 5000 System
- (2) 4Gbps ports
- (2) DataPacs
SEPATON S2100-ES2 virtual tape library (VTL)
- (2) 4Gbps ports
- (8) Logical tape drives configured
- Iometer benchmarks peg full duplex streaming I/O at 1,568MB per second.
- VOE D2VTL backup application throughput for NetBackup measured at 1,350 MB per second.
- VOE D2D backup application throughput for VCB proxy process measured at 500MB per second.
To test each HBA's ability to scale full-duplex streaming I/O, VSM Labs employed a RamSan-400 solid state disk (SSD) array with four 4-Gbit/sec FC controllers. We started a sequence of tests that simulated backup process streams, which are characterized by parallel reads and writes using large data blocks. All backup applications utilize large block I/O to enhance their ability to minimize IT Recovery Time Objectives (RTO).
We began by running a sequential stream of large 64KB read requests to one SSD drive and a second parallel write requests to another drive on the RamSan. Next, we initiated a second stream of reads and writes. With two sequential 64KB-read streams and two sequential 64KB-write streams, throughput for each HBA should have scaled to near-wire speed on both reads and writes: Only the Brocade 815 HBA scaled as expected.
Running full backups of eight VMs in parallel, our Windows-based HP Server used the VCB driver to read a shared ESX datastore in order to copy VM snapshot files to a local directory. With the Brocade 815 HBA installed in our proxy server, we measured full duplex throughput at roughly 500MB per second. Using the Emulex LPe12000 HBA with the 126.96.36.199 Emulex driver, we consistently measured full duplex throughput at around 360MB per second.
When we backed up the VM backup image files, which were created in our first test, to a VTL with eight logical drives, the Brocade 815 HBA sustained full duplex throughput at 1300MB per second. In this process, we read data from the Emprise 5000 storage system at 650MB per second and wrote backup images to the VTL at 650MB per second in perfect balance.