Hello. Our environment is: EVA3000 with 8 disks (72,8 GB) with one group disk and two virtual disks (80 GB RAID-1 and 300 GB RAID-5). Connected to the EVA is a ProLiant DL580, with Windows 2000 Advanced Server SP3 and SQL Server 2000 SP3a. The transaction logs are located in the 80GB virtual disk, and the database files are in the 300GB vd. We are comparing the performance with other server (ML750 with internal SCSI disks) and the results are DL580 much better than ML750 (more than 40% faster) while SQL is reading. But, when SQL is writing, the old machine is about 20% faster than the new one. We have also copied files from one virtual disk to the other and got 10 MB/sec. Any idea? Is there a way to improve writing operations in EVA3000 (for example, increasing buffers)? We have activated by default caching in writing and reading operations. Should we deactivate the read cache? Thanks in advance.
Add more disk drives to your disk group. The more drives in your disk group, the better the performance. (Theory) You are limited right now by the single shelf that the 3000 version has with it, go ahead and fully populate it.
This Advisory summarizes a potential performance issue resulting from uncorrected partition misalignment on StorageWorks Enterprise Virtual Arrays using "Vraid" Virtual Disks, and running either Windows 2000 or Windows Server 2003. Affects can be seen on both Vraid1 and Vraid5 units. In the event that performance issues are identified, a Windows Resource utility is available to create a disk partition that is properly aligned.
Windows applications that use EVA "Vraid" Virtual Disks for data stores may experience a write performance issue if partitions are not properly aligned. Performance data shows the impact to some applications may be significant. Data shows a greater impact is experienced on Vraid5 units than on Vraid1 units. Applications with multiple sequential write streams are more impacted than random write loads. The Windows DISKPAR utility will allow creating a disk partition that is properly aligned.
