[ZBX-4556] errors in documentation for "vfs.dev.read|write" key and not documented dependecy beetwen 2nd and 3rd parameters Created: 2012 Jan 17  Updated: 2017 May 30  Resolved: 2012 Mar 21

Status: Closed
Project: ZABBIX BUGS AND ISSUES
Component/s: Documentation (D)
Affects Version/s: None
Fix Version/s: 1.8.11, 2.0.0

Type: Incident report Priority: Minor
Reporter: Oleksii Zagorskyi Assignee: Unassigned
Resolution: Fixed Votes: 0
Labels: None
Remaining Estimate: Not Specified
Time Spent: Not Specified
Original Estimate: Not Specified
Environment:
  1. fdisk -l /dev/sda /dev/sdb | grep "/dev"
    Disk /dev/sda: 320.1 GB, 320072933376 bytes
    /dev/sda1 1 3648 29295616 fd Linux raid autodetect
    /dev/sda2 3648 8511 39062528 fd Linux raid autodetect
    /dev/sda3 8511 38914 244211712 fd Linux raid autodetect
    Disk /dev/sdb: 320.1 GB, 320072933376 bytes
    /dev/sdb1 1 3648 29295616 fd Linux raid autodetect
    /dev/sdb2 3648 8511 39062528 fd Linux raid autodetect
    /dev/sdb3 8511 38914 244211712 fd Linux raid autodetect
  1. cat /proc/mdstat
    md2 : active raid0 sda3[0] sdb3[1]
    md1 : active raid1 sda2[0] sdb2[1](F)
    md0 : active raid1 sda1[0] sdb1[1]

Issue Links:
Duplicate
is duplicated by ZBX-7270 vfs.dev.read and vfs.dev.write will r... Closed
is duplicated by ZBX-11519 vfs.dev.write|read return wrong values Closed

 Description   

Each part of documentation changes will be described in comments separately.
At first 1.8 doc will be fixed/improved and then 2.0 too.



 Comments   
Comment by Oleksii Zagorskyi [ 2012 Jan 17 ]

(1) 1st parameter "device" actually is optional - should be included in angle brackets <>
Default is "all" devices.

Comment by Oleksii Zagorskyi [ 2012 Jan 17 ]

(2) based on (1) a note could be added to documentation: included all block devices like sda, sbd and theirs sda1, sda2, sdb3 ... and multiple devices (MD raid) based on those block devices and logical volumes (LVM) based on those block devices.

Results of test just for case:

  1. zabbix_get -s 127.0.0.1 -k "agent.version"
    1.9.9
  1. RES=0; for i in sda sda1 sda2 sda3 sdb sdb1 sdb2 sdb3 md0 md1 md2; do let RES+=$(zabbix_get -s 127.0.0.1 -k "vfs.dev.write[$i,operations]"); done; echo $RES
    414839502
  1. zabbix_get -s 127.0.0.1 -k "vfs.dev.write[,operations]"
    414839502

Another host with LVM:

  1. RES=0; for i in sda sda1 sda2 mapper/pve-root mapper/pve-data; do let RES+=$(zabbix_get -s 10.20.0.31 -k "vfs.dev.write[$i,operations]"); done; echo $RES
    384642
  2. zabbix_get -s 10.20.0.31 -k "vfs.dev.write[,operations]"
    384642

the same for sectors, ops, sps.
Actually this behavior could be considered as "bad design" and will be discussed separately (in a ZBX).

<zalex> Has been discussed with Sasha. His point of view that firs parameter still should be optional, i.e. ability to monitor all available devises is enough useful and because should be supported.
So, the note has been added bottom of the table http://www.zabbix.com/documentation/1.8/manual/config/items?&#zabbix_agent
Please review.

Comment by Oleksii Zagorskyi [ 2012 Jan 17 ]

(3) 3rd parameter <mode> can be used only if 2nd parameter <type> is "sps, ops, bps". That should be noted in documentation in two tables: "Supported by platform" and "Zabbix Agent".
Should be added that it returns Float and Integer values.
Additionally should be explained briefly that "*ps" means * per second in the "Zabbix Agent" table.

Examples:

  1. zabbix_get -s 127.0.0.1 -k "vfs.dev.write[sda,,avg1]"
    196.400000
  2. zabbix_get -s 127.0.0.1 -k "vfs.dev.write[sda,sectors]"
    1558962393
  3. zabbix_get -s 127.0.0.1 -k "vfs.dev.write[sda,sectors,avg1]"
    ZBX_NOTSUPPORTED
  4. zabbix_get -s 127.0.0.1 -k "vfs.dev.write[sda,sps]"
    180.700000
  5. zabbix_get -s 127.0.0.1 -k "vfs.dev.write[sda,sps,avg1]"
    181.333333
  1. zabbix_get -s 127.0.0.1 -k "vfs.dev.write[,,avg1]"
    794.066667
  2. zabbix_get -s 127.0.0.1 -k "vfs.dev.write[,sectors]"
    8104448149
  3. zabbix_get -s 127.0.0.1 -k "vfs.dev.write[,sectors,avg1]"
    ZBX_NOTSUPPORTED
  4. zabbix_get -s 127.0.0.1 -k "vfs.dev.write[,sps]"
    837.600000
  5. zabbix_get -s 127.0.0.1 -k "vfs.dev.write[,sps,avg1]"
    855.200000

<zalex> Tested just for case. Parameters sps and ops really are "values per second".

Comment by Oleksii Zagorskyi [ 2012 Jan 17 ]

(4) default value for "vfs.dev.read|write" actually is different for different OS but not "sectors" as noted in a table "Supported by Platform".
How this error happened: my error !
It appeared in a revision when I've changed table's "columns style" http://www.zabbix.com/documentation/1.8/manual/config/items?rev=1293663369
I remember this **single** case when I doubted but at the end I've added a word (default) to "sectors". Sorry on that, should be removed.

But I'm going to add a note to first column, so it will be: "type (defaults are different under various OSes)".
I consider this as very important, especially because the tables located at the different pages in 2.0 doc.

Comment by Oleksii Zagorskyi [ 2012 Jan 27 ]

(1), (3), (4) RESOLVED in http://www.zabbix.com/documentation/1.8/manual/config/items
(2) resolved too.
RESOLVED, 2.0 documentation will be updated after approval of these changes.

<zalex> Approved by Martins (IRC), 2.0 doc has been updated.
CLOSED.

Issue CLOSED

Generated at Wed Jul 30 03:23:59 EEST 2025 using Jira 9.12.4#9120004-sha1:625303b708afdb767e17cb2838290c41888e9ff0.