Hello Everyone, I have a Red Hat Enterprise Linux 4 box (32 bit) running version 5.1.2 of net-snmp.
I'm trying to capture disk IO information. This is what snmp gives me for the disk that I'm interested in. UCD-DISKIO-MIB::diskIOIndex.25 = INTEGER: 25 UCD-DISKIO-MIB::diskIODevice.25 = STRING: dm-2 UCD-DISKIO-MIB::diskIONRead.25 = Counter32: 0 UCD-DISKIO-MIB::diskIONWritten.25 = Counter32: 677224960 UCD-DISKIO-MIB::diskIOReads.25 = Counter32: 32441872 UCD-DISKIO-MIB::diskIOWrites.25 = Counter32: 1814665690 Notice that the diskIONRead counter is 0. This is what I get for device dm-0 on the same system. UCD-DISKIO-MIB::diskIOIndex.22 = INTEGER: 22 UCD-DISKIO-MIB::diskIODevice.22 = STRING: dm-0 UCD-DISKIO-MIB::diskIONRead.22 = Counter32: 2239779840 UCD-DISKIO-MIB::diskIONWritten.22 = Counter32: 3443953664 UCD-DISKIO-MIB::diskIOReads.22 = Counter32: 3552815 UCD-DISKIO-MIB::diskIOWrites.22 = Counter32: 37540969 I wonder if there is an overflow that is causing the counter to show 0. The code that generates these counters gets its data from /proc/diskstats. Here is the associated line from that file. 253 2 dm-2 32447368 0 1814764522 152337767 64442309 0 515538472 359442735 0 176453907 511782733 Here is the dm-0 line also, in case it is useful. 253 0 dm-0 3555684 0 390341218 11890071 37571579 0 300572632 887962651 0 71276923 899882155 >From this, it looks like the number of sectors read on dm-2 is 1814764522. The code then goes on to multiply that number by 512. 929159435264 is the answer I get. That certainly is a large number, but I believe that even if it gets truncated, I should still get some value other than 0. Is there a way to clear the counters that the kernel maintains? Since this is a production box, I can't just reboot it to see if smaller numbers will cause it to work as expected. I do have another box that isn't production that is configured similarly. I'm currently doing many reads against it now in hopes that after I surpass some number of sectors read that it will exhibit the same issue. Has anyone had this problem before? Am I missing something obvious? Does anyone know of a way to manipulate the disk counters that the kernel maintains? Thanks, Jack Dozier ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ Net-snmp-users mailing list [email protected] Please see the following page to unsubscribe or change other options: https://lists.sourceforge.net/lists/listinfo/net-snmp-users
