On 13 Jun 2008, at 23:38, Mohit Anchlia wrote:
look at "sar" output and see the wait times on the disk is more than the service time.
That command doesn't seem to exist on FreeBSD. Do you know if there's an equivalent command?
-Stut
On 6/13/08, Stut <stuttle@xxxxxxxxx> wrote: On 13 Jun 2008, at 22:56, Dragon wrote: Stut wrote: On 13 Jun 2008, at 22:37, Dragon wrote: Stut wrote: Hi, I have a problem with one of the web servers I manage. It runs FreeBSD6.2, Apache 2.2.8 and PHP 5.2.1. It runs a high-ish number of pre- forkprocesses (usually around 240). What basically happens is that during our peak hours in the evening the site becomes very slow as does everything on the server. The top output shows nearly all httpd processes in the state "devfs" and the load is jumping up over 10 but the CPU is 70% idle. There's plenty of free memory, over 4GB, and lots of available disk space. While it's in this state all disk access is painfully slow. I've checked all the drives and the RAID card status and everything appears to be fine. It also recovers itself after a few hours when the traffic dies down again. I've spent a lot of today Googling but can't find any reference to this particular combination of symptoms. Does anyone have any ideas? ---------------- End original message. --------------------- It sounds to me like your system is waiting on disk resources (I am assuming that is what the devfs state is), it is very likely trying to use swap space. Now much memory does this system have? If it has insufficient memory to keep most things in RAM, it is going to use a lot of swap and that will slow things down considerably. Oh how I wish it were that simple... Mem: 1629M Active, 770M Inact, 392M Wired, 68K Cache, 214M Buf, 4791M Free Swap: 8192M Total, 8192M Free No swap in use, plenty of free memory. ---------------- End original message. ---------------------Well, I took my best shot on the info presented. I still think there is something in the disk I/O path that is acting as a bottleneck.Sorry it isn't so easy, I have nothing else here. Wish I could help. No worries, thanks for trying.I agree that it's probably disk-related, but other than these symptoms I can't find anything wrong.I'll see if the FreeBSD list can help. -Stut -- http://stut.net/ ---------------------------------------------------------------------The official User-To-User support forum of the Apache HTTP Server Project.See <URL:http://httpd.apache.org/userslist.html> for more info. To unsubscribe, e-mail: users-unsubscribe@xxxxxxxxxxxxxxxx " from the digest: users-digest-unsubscribe@xxxxxxxxxxxxxxxx For additional commands, e-mail: users-help@xxxxxxxxxxxxxxxx
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