On Tue, Jul 15, 2008 at 2:02 PM, April Jenner aprilogi@yahoo.com wrote:
Hello toasters,
i have several volume deswizzling processes runing. This is ok, why i copy the volume with snapmirror from
one aggr to another.
This volume deswizzling processes now running for more
than a month.
This is normal and okay. If you aren't having any performance problems, then I'd allow it to continue.
I wouldn't be so quick to judge normality. A month for deswizzling is IMHO far far too long, and indicative of a either an extreme workload (lots of inode churn) or a system interaction causing the deswizzler to not progress. Both of these should be considered even if you don't see any clear performance problems. You may only see issues sporadically, or it may only be noticeable during certain kinds of workload. If nothing else, assuming bugs or issues aren't ruled out, it may be an indicator of an undersized head. I've found deswizzler issues to be fairly insidious.. since they tend to use a fair amount of RAM at times, and can have dramatic effects coupled with certain types of operations (such as ndmp backups), and the deswizzler itself can have odd behaviors (as previously mentioned).
--Dave
What version? There have been big improvements in 7.2 and dot releases.
Now the question: When i stop the deswizzling with "wafl scan
abort", can i restart them one by one to finish them a bit faster?
What is the command?
The big question here is whether or not you are having a performance problem caused by deswizzling. If performance is okay, I'd let it go.
Be careful of changing the values for wafl scan. You can cause problems by using the wrong settings. Changing the value for wafl scan effects more then deswizzling and in general is considered a bad idea.
If you believe you are having performance problems, it might be worth calling support and asking them help you evaluate your system. Other things might be a problem.
One last question, if you precieve a performance problem, do you have any measurements such as timing the time it takes to write a file or looking at perfstat output? Just curious.
--April