![quick disk drive quick disk drive](http://blog.sqlauthority.com/i/b/Floppy-Disk-Coasters.jpg)
Yes to check bad performance you can check the queue length if its grater than 2 for any disk. Therefor Without a map disk queue length is meaningless and unable to help you finding the root cause. Multiple drives configured for the LUN this is RAID 0+1 see 2 73G drives configured up a 59.39G formatted capacity): Such as an example what a mapping look like. How many disks are participating in with vendor configuration example as EMC hyper volume. Problem with queue length Orion user will be not be able to provide and understand disk map how the SAN is configured to see and understand all the logical volumes. If the E: is a logical disk composed of 8 physical disks, then it’s not an issue Why? 8 disks x 2 queue length = 16 > DBA sees 10 so 10 is less than 16 matching our threshold therefor this is not an issue. Īs an example customer DBA monitor perfmon and found the disk queue length is 10 on drive E: certainly this is a high number, Now If the E: is one physical disk, yes, you have a problem. So if i will start covering everything here this topic will never end when encompassing all of those varying configurations. May have various disk types (SCSI, SSD, SATA) as well as RAID applications and you have quite a complex set of information to work with in rooting out performance issues. Ĭustomer may have direct attached, PCIe, iSCSI and Fiber channel to a wide range of SAN equipment. You may have a range of disk configurations as each company has their own configuration standards they might heave for existing running SQL server with their own philosophy on serving storage to the production servers where they just placed the Orion DB.
![quick disk drive quick disk drive](https://data2.manualslib.com/first-image/i1/1/11/1028/acer-external-hard-disk-drive-500gb.jpg)
Īs technology is growing in the area of high end storage and now a days it’s almost impossible / difficult to find out an accurate metric and calculation if this is really good or bad configuration. What can be quickly check to get an idea and the logic behind considering the configured environment. In this article I have just included a quick performance check for SQL disks.