2.5 io statistics?
Is there a writeup of the changes anywhere? I'd like to port cstat to 2.5. Cstat is sort of a netstat/vmstat combo:
load free cach swap pgin pgou dk0 dk1 dk2 dk3 ipkt opkt int ctx usr sys idl 0.00 19M 562M 48M 4.0K 12K 0 0 0 0 137 25 267 83 0 0 100 0.00 18M 563M 48M 0 12K 0 0 0 0 133 22 258 77 0 1 99
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--- Larry McVoy lm at bitmover.com http://www.bitmover.com/lm
Quoted 7 lines · Larry McVoy
Is there a writeup of the changes anywhere? I'd like to port cstat to 2.5. Cstat is sort of a netstat/vmstat combo:
load free cach swap pgin pgou dk0 dk1 dk2 dk3 ipkt opkt int ctx usr sys idl 0.00 19M 562M 48M 4.0K 12K 0 0 0 0 137 25 267 83 0 0 100 0.00 18M 563M 48M 0 12K 0 0 0 0 133 22 258 77 0 1 99
It's currently undergoing a bit of change.
In 2.5.67 all IO activity is monitored by opening and reading /sys/block/hda/stat. This certainly doesn't scale when you have thousands of disks, so there's a patch in -mm which performs runtime aggregation of global stats and exposes that via /proc/diskstats.
So if you want to monitor the "global" IO activity, you don't need to open all those sysfs files.
I don't know if the aggregate disk stats patch is ready to go yet. I'm awaiting testing results, conversion of userspace tools, etc. I just plonked it in there and haven't heard anything since.
As far as I know, neither the format of the sysfs file nor the format of /proc/diskstats is documented anywhere.
Perhaps Rick can prepare a description for inclusion under Dcumentation/ somewhere?
As far as I know, neither the format of the sysfs file nor the format of /proc/diskstats is documented anywhere.
Perhaps Rick can prepare a description for inclusion under Dcumentation/ somewhere?
Happy to do so. I will try to have it done within a week.
Rick
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load free cach swap pgin pgou dk0 dk1 dk2 dk3 ipkt opkt int ctx usr sys idl
0.00 19M 562M 48M 4.0K 12K 0 0 0 0 137 25 267 83 0 0 100It's currently undergoing a bit of change.
Well, one question is this: I'd like to be able to get at a list of disk stats sorted by activity. If you noticed, the output above reserved space for 4 drives. I know it's not general at all, but it would be nice to somehow be able to get at the "busy" drives. I don't have any ideas on how to do this generally and that might mean it isn't possible but maybe (I hope) it means I'm tired and not thinking clearly. Anyone have any ideas?
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--- Larry McVoy lm at bitmover.com http://www.bitmover.com/lm
Hi!
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load free cach swap pgin pgou dk0 dk1 dk2 dk3 ipkt opkt int ctx usr sys idl
0.00 19M 562M 48M 4.0K 12K 0 0 0 0 137 25 267 83 0 0 100It's currently undergoing a bit of change.
Well, one question is this: I'd like to be able to get at a list of disk stats sorted by activity. If you noticed, the output above reserved space for 4 drives. I know it's not general at all, but it would be nice to somehow be able to get at the "busy" drives. I don't have any ideas on how to do this
Perhaps top-3 then sum of rest is better
idea (perhaps you do that already...)
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