Good Post by Duncan Epping (thank you)
A while ago I wrote an article about the queue depth of certain disk controllers and tried to harvest some of the values and posted those up. William Lam did a “one up” this week and posted a script that can gather the info which then should be posted in a Google Docsspreadsheet, brilliant if you ask me. (PLEASE run the script and lets fill up the spreadsheet!!) But some of you may still wonder why this matters… (For those who didn’t read some of the troubles one customer had with a low-end shallow queue depth disk controller, and Chuck’s take on it here.) Considering the different layers of queuing involved, it probably makes most sense to show the picture from virtual machine down to the device.
Read on here