[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]

[dm-devel] Re: Reducing amount of logmessages openiscsi/multipath [with md3000i]



Kees Hoekzema wrote:
Hello List,

I am adding the dm-devel list.

I think you want different settings in your multipath conf. For example it looks like you are using directio to test paths and you want TUR or the md3000i specific one which does not cause IO errors to passive paths.

You also want to make sure that you are using the md3000i hw handler or scsh_dh_module if you are not already. The dm-devel guys can help you out.

You may want to post your multipath.conf on the thread.


Recently we bought a md3000i for our storage needs. This box comes with two
redundant controllers and both controller has two networkports. We connected
all four ports to our testing network, and I let some servers mount the
md3000i. The goal is to have all four connections on the server available
with a redundant network, so that we can failover if one switch dies or if a
controller dies.

However, the controller does not have support an active-active state, which
means that if you open four connections to the four ports, you will get two
faulty connections. With multipath this isn't a big problem as it can see
fairly quick if a controller is offline and it switches to the other
controller:

$ multipath -ll
webdata (36001ec9000d163110000067f484e260c) dm-0 DELL    ,MD3000i
[size=2.0T][features=0][hwhandler=0]
\_ round-robin 0 [prio=1][enabled]
 \_ 4:0:0:0 sda 8:0   [active][ready]
\_ round-robin 0 [prio=1000][active]
 \_ 5:0:0:0 sdb 8:16  [active][ready]
\_ round-robin 0 [prio=0][enabled]
 \_ 6:0:0:0 sdc 8:32  [active][faulty]
\_ round-robin 0 [prio=0][enabled]
 \_ 7:0:0:0 sdd 8:48  [active][faulty]

(yes, I know the prio's are a bit strange, but that is to test something
else).

This all works quite well, but the problem we have is a massive amount of
spam in dmesg / kern.log / syslog. In syslog we get this every 3 seconds:
Aug 19 14:54:12 abaris kernel: [691035.298493] end_request: I/O error, dev
sdc, sector 0
Aug 19 14:54:12 abaris kernel: [691035.366443] end_request: I/O error, dev
sdd, sector 0
Aug 19 14:54:13 abaris multipathd: sdc: directio checker reports path is
down
Aug 19 14:54:13 abaris multipathd: sdd: directio checker reports path is
down

This is of course useful information, but to get this 28.800 times per day
in your log is a waste of space, beside making it impossible to read other
messages without grepping. Now this can still be reduced by adding some
syslog filters, but the other problem is dmesg:

$ dmesg
[691098.658507] end_request: I/O error, dev sdc, sector 0
[691098.704036] end_request: I/O error, dev sdd, sector 0
[691101.678930] end_request: I/O error, dev sdc, sector 0
[691101.738252] end_request: I/O error, dev sdd, sector 0

And this goes on for every 3 seconds as long as the connection is logged in.

So my questions:
- Is there a way to suppress those messages, either in the iscsi programs or
in multipath?
- If that fails, is it possible to tweak multipath in such a way that it
doesn't check the two failed paths, unless there is no other path available?
These two paths should become available only if the main controller dies.

Thanks in advance,
Kees Hoekzema


--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups "open-iscsi" group.
To post to this group, send email to open-iscsi googlegroups com
To unsubscribe from this group, send email to open-iscsi+unsubscribe googlegroups com
For more options, visit this group at http://groups.google.com/group/open-iscsi
-~----------~----~----~----~------~----~------~--~---



[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]