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psychotic_savage
Starting Member
25 Posts |
 Posted - 2011-06-08 : 02:47:29
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| Hi All.Does the size of a databases log file effect the speed at which data hardens on the mirror.I have around 15 x 10gig log files on the mirror.I have also set the 3499 flag (which by my understanding is meant to reply to the querying principle that the request has been completed before it is hardened on the mirror)I am getting notifications on the mirror:SQL Server has encountered 4036 occurrence(s) of I/O requests taking longer than 15 seconds to complete.Can I reduce these occurrences by ensuring the log files remain smaller than they currently are?Thanks |
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GilaMonster
Master Smack Fu Yak Hacker
4507 Posts |
Posted - 2011-06-08 : 04:17:30
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| That's not a size issue. That's an IO performance issue. Your IO subsystem can't keep up with the load being placed on it.Reduce the log size and you'll likely see one of two things - log file grow operations, out of log space errors--Gail ShawSQL Server MVP |
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psychotic_savage
Starting Member
25 Posts |
Posted - 2011-06-08 : 05:26:56
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| I was hoping I could alleviate some of the load by working with the log files but alas :(The strange part is that I can run all the DB's as the principles on Svr4 with less IO problems than when everything is mirrored to said server (Svr4) with Svr1,2 and 3 as the principle.IE.Svr1 - PrincipleSvr2 - PrincipleSvr3 - PrincipleSvr4 - MirrorAny ideas why this would be? |
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GilaMonster
Master Smack Fu Yak Hacker
4507 Posts |
Posted - 2011-06-08 : 05:44:50
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| Size of log files in no way affects the IO performance.Possibly because when all three are on one server there's some other resource bottleneck (CPU or memory) that the servers are running into long before the log writes overwhelm the IO subsystem.--Gail ShawSQL Server MVP |
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tkizer
Almighty SQL Goddess
38200 Posts |
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Log files (.ldf) sizes and mirroring