Hi,
I have modified the previous dm logging patch to print logs in more user friendly format.
Ex :
Nov 9 16:45:04 localhost kernel: device-mapper: multipath: [dm-1] Switching to pathgroup index 1
Nov 9 16:45:04 localhost kernel: device-mapper: multipath: [dm-1] Selecting path sdc for I/O
This new patch includes following changes:
- printing "[dm-*]" instead of "major:minor"
- Added 3 macro functions for logging
# define DMLOG(..)
* It should be used when we just want to print message without device name.
Prototype : #define DMLOG(SHIFT, LEVEL, f, arg...)
Usage ex: DMLOG(DMLOG_INIT, DMLOG_INFO, "cleaned up");
# define DMLOG1(..)
* prints device name with messages
* (struct mapped_device * ) needs to be passed as 3rd argument to this macro function
Prototype : #define DMLOG1(SHIFT, LEVEL, MAPPED_DEVICE, f, arg...)
Usage ex: DMLOG1(DMLOG_IOCTL, DMLOG_INFO, md, " Setting DMF_NOFLUSH_SUSPENDING flag");
# define DMLOG2(..)
* prints device name with messages
* (struct dm_target * ) needs to be passed as 3rd argument to this macro function.
(Typically to be used by target)
Prototype : #define DMLOG2(SHIFT, LEVEL, DM_TARGET, f, arg...)
Usage ex: DMLOG2(DMLOG_IOCTL, ti, "Unrecognised multipath message received.");
How to set logging level :
---------------------------
[copy paste from my previous mail]
1) On-the-fly by setting /sys/module/dm_mod/parameters/dm_logging_level.
For example: To enable DMLOG_INIT logs for all ERROR (i.e DMLOG_ERR level) and DMLOG_ADD_DEV logs at DMLOG_INFO level, we can set as
follows:
4 2 0
|_|_|_|_|
1 1 0 1 -->0x0d or 13
echo 0x0000000d > >/sys/module/dm_mod/parameters/dm_logging_level
or
echo 13 >/sys/module/dm_mod/parameters/dm_logging_level
2) At boot time using modprobe.conf:
options dm-mod dm_logging_level=13
------------------------------------------------------------------------------
dm_logging_level bitwise representation (2 bit reserved for each logging type)
------------------------------------------------------------------------------
20 18 16 14 12 10 8 6 4 2 0
......|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|
\ \ \ \ \ \ \ \ \ \_DMLOG_INIT
\ \ \ \ \ \ \ \ \_DMLOG_ADD_DEV
\ \ \ \ \ \ \ \_DMLOG_REMOVE_DEV
\ \ \ \ \ \ \_DMLOG_IOCTL
\ \ \ \ \ \_DMLOG_IO
\ \ \ \ \_DMLOG_UEVENT
\ \ \ \_DMLOG_TABLE
\ \ \_DMLOG_FAILOVER
\ \_DMLOG_PATH_ACTIVATE
\_DMLOG_PATH_DEACTIVATE
snippet of syslog with new logging patch:
===============================================
Nov 9 21:33:29 localhost kernel: device-mapper: multipath: version 1.1.0 loaded
Nov 9 21:33:29 localhost kernel: device-mapper: dm-path-selector: path selector round-robin registered successfully
Nov 9 21:33:29 localhost kernel: device-mapper: multipath round-robin: version 1.0.0 loaded
Nov 9 21:33:29 localhost kernel: device-mapper: dm-path-selector: path selector module round-robin Loaded successfully
Nov 9 21:33:29 localhost kernel: device-mapper: ioctl: 3600a0b80003908f9000047ec4a10b680: Creating dm device
Nov 9 21:33:29 localhost kernel: device-mapper: ioctl: [dm-0] Inserting in hash table
Nov 9 21:33:29 localhost kernel: device-mapper: ioctl: [dm-0] Successfully inserted in hash table
Nov 9 21:33:29 localhost multipathd: 3600a0b80003908f9000047ec4a10b680: load table [0 2097152 multipath 2 pg_init_retries 49 1 rdac 2 1 round-robin 0 1 1 8:16 1000
Nov 9 21:33:29 localhost kernel: device-mapper: ioctl: 3600a0b80003910f3000058264a7e46cb: Creating dm device
Nov 9 21:33:29 localhost kernel: device-mapper: ioctl: [dm-1] Inserting in hash table
Nov 9 21:33:29 localhost kernel: device-mapper: ioctl: [dm-1] Successfully inserted in hash table
Nov 9 21:33:29 localhost multipathd: 3600a0b80003910f3000058264a7e46cb: load table [0 20971520 multipath 2 pg_init_retries 49 1 rdac 2 1 round-robin 0 1 1 8:32 1000
Nov 9 21:33:29 localhost multipathd: 3600a0b80003908f9000047ec4a10b680: event checker started
Nov 9 21:33:29 localhost multipathd: 3600a0b80003910f3000058264a7e46cb: event checker started
Nov 9 21:33:29 localhost multipathd: path checkers start up
Nov 9 21:33:29 localhost kernel: device-mapper: multipath: [dm-1] Switching to pathgroup index 1
Nov 9 21:33:29 localhost kernel: device-mapper: multipath: [dm-1] Selecting path sdc for I/O
Nov 9 21:33:29 localhost kernel: device-mapper: multipath: [dm-1] pg_init_done: failover status = 0
Nov 9 21:33:30 localhost kernel: device-mapper: multipath: [dm-0] Switching to pathgroup index 1
Nov 9 21:33:30 localhost kernel: device-mapper: multipath: [dm-0] Selecting path sdb for I/O
Nov 9 21:33:30 localhost kernel: device-mapper: multipath: [dm-0] pg_init_done: failover status = 0
Please give your comments.
Thanks,
Vijay
On September 07, 2009 12:59 PM, Chauhan, Vijay wrote :
>
> On Sun, Sep 6, 2009 at 5:03 AM, Alasdair G Kergon
> <agk@xxxxxxxxxx> wrote:
> > > Each logging type is represented with 2 bits in
> > dm_logging_level. Following are the logging types
> currently defined :
> >
> > Does that mean there's a limit we'll soon exceed?
>
> Yes true. In that case we can further split the logging
> across the targets , such as multipath, linear so on. Your
> thoughts please.
>
> >
> > > Sep 5 18:32:02 localhost kernel: device-mapper: core:
> > DEBUG: dm_resume: Unsetting DMF_SUSPENDED flag for 253:1
> >
> > I was hoping the next extension to the macro code would
> > somehow add info
> > like '253:1' (and maybe corresponding device name) automatically to
> > every message related to a device.
> >
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