I hard-coded the chunk size for all of my machines because I thought the default was 16. 16 is what is mentioned for a disk scan in the afsd manpage. I hadn't heard about autotuning the chunksize before. A chunksize of 18 (256KB seemed like a good value when I configured my machines.
If I increase the chunksize of let it default to 20, will that result in fewer cache files and a faster cache scan? What is the algorithm for auto-tuning the chunksize, or where can I find it? Is there a way to measure how effective the chunksize is on a live system? Thanks, Jason --------------------------------------------------------------------------- Jason Edgecombe | Linux and Solaris Administrator UNC Charlotte | The William States Lee College of Engineering 9201 University City Blvd. | Charlotte, NC 28223-0001 Phone: 704-687-3514 [email protected] | http://coe.uncc.edu --------------------------------------------------------------------------- If you are not the intended recipient of this transmission or a person responsible for delivering it to the intended recipient, any disclosure, copying, distribution, or other use of any of the information in this transmission is strictly prohibited. If you have received this transmission in error, please notify me immediately by reply e-mail or by telephone at 704-687-3514. Thank you. -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Andrew Deason Sent: Wednesday, January 26, 2011 4:42 PM To: [email protected] Subject: [OpenAFS] Re: Reducing cache scan time On Wed, 26 Jan 2011 15:58:30 -0500 "Edgecombe, Jason" <[email protected]> wrote: > My afsd options are "-fakestat -dynroot -chunksize 18 -stat 500000 > -daemons 16 -volumes 2000 -blocks 59535014 . I dynamically add the block > option based on the size of the cache partition. Any particular reason for the "-chunksize 18" ? That should default to 20 for a cache of that size, which normally I think you'd want. Increasing it further may help, as it should result in fewer cache files. You can tweak the -files argument directly, which should affect the cache scan (if you start afsd with -verbose, it will tell you what it defaulted to with "cacheFiles autotuned to X"). But that could affect cache performance after you start, since that dictates how many chunks you can store in the cache. -- Andrew Deason [email protected] _______________________________________________ OpenAFS-info mailing list [email protected] https://lists.openafs.org/mailman/listinfo/openafs-info _______________________________________________ OpenAFS-info mailing list [email protected] https://lists.openafs.org/mailman/listinfo/openafs-info
