>>> On 2/17/2010 at 08:49 AM, "Mrohs, Ray" <[email protected]> wrote: > Hi, > We are running SLES10 and WebSphere on 1 IFL and 2G storage. These > bursts of activity seem to happen every few hours. > Is occasional swapping in the thousands too high if its going to VDISK?
No. The numbers you show are actually quite low. > What can cause the high 'wa' values? Our info is limited since this is a > test partition with no VM performance monitoring (yet). As Rob mentioned, %wa is the percentage of time the system was waiting for I/O to complete, and nothing else was running at that moment. When overall CPU use is very low, as in your case, just about any I/O will result in very high %wa numbers. I only see 4 instances of more than trivial CPU use in your vmstat output. The pattern of swap out versus swap in is rather unusual, but not necessarily anything to worry over. As Rob also pointed out, you have a very large amount of storage out on paging space (700-850MB), and very little free/buffer/cache. Since your paging *rates* aren't terribly high, this may just be a lot of unused code getting paged out. The main concern I would have is if the usage pattern changes and a lot more of that would need to be "in" and not "out" you could run into page thrashing. Things could get very ugly very fast in that case. Since it is just a test machine, you might not want to spend much time doing anything about it, but keep an eye on it as time goes on. Mark Post ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
