To analyze queue length data further, use Avg. Disk Read Queue Length and Avg. Disk Write Queue Length. Does this answer your question? Sort of Last week, I spent 30 minutes telling my supervisor that performance monitor does not average its staticstics together - it only records the data from a point in time. Then he challenged me: "What about all those average counters?
The definition of average is at least two data points. Disk Queue Length" where it states: "Tracks the number of requests that are queued and waiting for a disk during the sample interval" - what does that mean? It states "Sample interval" - are those the two data points? For instance, if at it is a value of 1, and the actual reading is a value of 2, does it instead average the and entry and write in 1. Or does "Average" mean, at the sample time say pm , it is looking at all data trying to enter the hard disk, and some of that data coming in has a queue length of 1 and some have a queue length of two - and at that data point sample interval it will take all that and average those incoming requests to the hard drive and put that down as the value at pm?
It looks like nobody every replied to your last question, and it's an answer I'd love to know. I am using a script to retrieve from WMI the values for several objects and counters, and some of the values I get back make no sense at all, especially the disk ones. For example:. What do any of those numbers mean? What unit are they measuring? With the values returned being so astronomical it's hard to even guess what they could be.
How do I convert those numbers into something that means something? For example, some of the web postings I've seen related to AvgDiskReadQueueLength indicate that values over 1 or 2 are a bad sign. Well, in that case, I guess my machine is near death at How do I equate those values to a number like ? All those numbers do nothing but go up So to find out how bad things were between my two readings, do I need to subtract one from the other and divide by some magic number and then take the inverse reciprocal of the square root?
I read some posts that say throw more spindles at it My second question is this. I have an EqualLogic iscsi array on the network now. I configured an exchange volume and was planning on putting the exchange information store onto the array.
XMSRE is the performance guru so if you want the best answer possible wait for his response. If you see average response times greater than 20ms or peaks lasting more than a few seconds over 50ms, then your IO subsystem is performing poorly.
RAID 10 has a write penalty of 2. RAID 5 has a write penalty of 4. I'd go with RAID 10 for the databases. One volume is 7TB for general file storage on one server and the other volume is 1.
Are your clients cached? Are you running BlackBerry? Any desktop search engines? If it's only IOPS, then the load is small enough that it really won't matter what you use. In that you are experiencing problems, I would assume that this is not the case. Figure out what your IO load is, then you'll have the information you need to configure your storage in a way that will support that load.
Yes all clients are cached but maybe 20 have blackberries. No desktop search engines that I know of. Here are our results on the performance monitor scale Your average latencies are 25ms for the sampling period. Your current disk subsystem is performing poorly. These numbers assume 8K random IO at a response time of 20ms or less. In addition, they take into account the overhead of the NTFS file system. How that translates into spindle count depends on the tpye of disk and the type of RAID array.
A mirror should easily handle this. XM, it never ceases to amaze me how you can know that much detail about this stuff. Star for you just for that. Knowing we don't have any money to spend, I think our only and best option here is to leave the OS on the C: drive mirrored, the logs on the D: drive mirrored and move the db to the EqualLogic Knowing the configuration is not optimal, let's see if it could work.
I believe you initially stated this is a 16 disk RAID 50 array. OS goes on a mirror, check. Either place, with the OS or with the DBs is not a good solution.
I believe you will continue to see performance issues. I will have to start poking around on procedures. I've seen that it might be able to be done within system manager The best answers are voted up and rise to the top.
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Active 12 years, 5 months ago. Viewed 1k times. Improve this question. Mark Amerine Turner. Mark Amerine Turner Mark Amerine Turner 2, 1 1 gold badge 16 16 silver badges 17 17 bronze badges. What is the storage? Is it a RAID array or just a single disk or what?
I'm interested in the cache section — Matt Rogish. Added a link to the full output pastie. Show 5 more comments. Active Oldest Votes. Looking at the sysmon, you're attempting to do Am in particular interested in this line: max memory memory pages 2k dynamic It's possible that you may have enough memory assigned to ASE, but you've not added it to the data cache. Improve this answer.
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