Re: [CentOS] Qlogic HBA scanning issues with CentOS 5.1 ?

[Filipe Brandenburger]

On Dec 17, 2007 9:34 AM, Filipe Brandenburger <[EMAIL PROTECTED]> wrote:

> On 2.6 kernels, I always used to issue the commands directly:
>

This was actually introduced in CentOS 4.3 (and upstream RHEL4.3):
http://www.centos.org/docs/4/html/release-notes/as-x86/RELEASE-NOTES-U3-en.html#id3641770

Filipe
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Re: [CentOS] Qlogic HBA scanning issues with CentOS 5.1 ?

[Filipe Brandenburger]

Hi,

On 2.6 kernels, I always used to issue the commands directly:

1) Find what's the host number for the HBA:

ls /sys/class/fc_host/

(You'll have something like host1 or host2, I'll refer to them as
host$NUMBER from now on)

2) Ask the HBA to issue a LIP signal to rescan the FC bus:

echo 1 >/sys/class/fc_host/host$NUMBER/issue_lip

3) Wait around 15 seconds for the LIP command to have effect

4) Ask Linux to rescan the SCSI devices on that HBA:

echo - - - >/sys/class/scsi_host/host$NUMBER/scan

The wildcards "- - -" mean to look at every channel, every target, every
lun.

That's it. You can look for log messages at "dmesg" to see if it's working,
and you can look at /proc/scsi/scsi to see if the devices are there.

These commands should work with all HBAs, at least I know for sure they work
with QLogic's and Emulex'es.

Hope it helps,
Filipe
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Re: [CentOS] Qlogic HBA scanning issues with CentOS 5.1 ?

[Finnur Örn Guðmundsson]

Fabian Arrotin wrote:

On Fri, 2007-12-14 at 21:55 +, Finnur Örn Guðmundsson wrote:
  

Hi,

I got few servers (IBM HS20,HS21 blades, IBM xSeries 3650 & others) 
connected to a dual fabric san throught Qlogic HBA's (23xx, 24xx). 
Multipathing is done with device-mapper-multipath.



I've installed the same machines on several IBM DS3xxx or DS4xxx SANs
but i used the provided rdac multipath driver (adviced by IBM in their
documentation)

  
On CentOS 4.x i can scan for new scsi devices without any problems, get 
them up with multipathing & use them without any problems.


However, after i started installing CentOS 5.1 (did not notice this 
problem with CentOS 5) i cannot seem to rescan without huge problems. 
Sometimes when i rescan after presenting a new LUN to the server nothing 
is detected, and sometimes the device comes in without any problems at 
all. Sometimes i even loose some paths after rescanning.again, i had 
no problems at all with CentOS 4.x.


I use the Qlogic script (Dynamic Target and LUN Discovery 
 
2.2) to scan for new luns.



As already said, the rdac driver/userspace tool contains a hot_add
script that takes care of that .. but i admit that i've not yet updated
those machines to 5.1 because of a need to rebuild the rdac kmod ...
  
Has anyone had any issues with scanning for new devices off san after 
upgrading to 5.1 ?


Thanks,
Finnur




  



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Hi,

Sorry, forgot to mention i got a IBM SVC as a storage device. IBM 
recommends using device-mapper-multipath for RHEL 5. There is not SDD 
(propriatory IBM driver for the ESS, DS6000/DS8000, SVC devices) for RHEL 5.



Bgrds,
Finnur
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Re: [CentOS] Qlogic HBA scanning issues with CentOS 5.1 ?

[Fabian Arrotin]

On Fri, 2007-12-14 at 21:55 +, Finnur Örn Guðmundsson wrote:
> Hi,
> 
> I got few servers (IBM HS20,HS21 blades, IBM xSeries 3650 & others) 
> connected to a dual fabric san throught Qlogic HBA's (23xx, 24xx). 
> Multipathing is done with device-mapper-multipath.

I've installed the same machines on several IBM DS3xxx or DS4xxx SANs
but i used the provided rdac multipath driver (adviced by IBM in their
documentation)

> 
> On CentOS 4.x i can scan for new scsi devices without any problems, get 
> them up with multipathing & use them without any problems.
> 
> However, after i started installing CentOS 5.1 (did not notice this 
> problem with CentOS 5) i cannot seem to rescan without huge problems. 
> Sometimes when i rescan after presenting a new LUN to the server nothing 
> is detected, and sometimes the device comes in without any problems at 
> all. Sometimes i even loose some paths after rescanning.again, i had 
> no problems at all with CentOS 4.x.
> 
> I use the Qlogic script (Dynamic Target and LUN Discovery 
> 
>  
> 2.2) to scan for new luns.

As already said, the rdac driver/userspace tool contains a hot_add
script that takes care of that .. but i admit that i've not yet updated
those machines to 5.1 because of a need to rebuild the rdac kmod ...
> 
> Has anyone had any issues with scanning for new devices off san after 
> upgrading to 5.1 ?
> 
> Thanks,
> Finnur


-- 
Fabian Arrotin <[EMAIL PROTECTED]>
Solution ? 
echo '16i[q]sa[ln0=aln100%Pln100/snlbx]sbA0D4D465452snlbxq' | dc


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[CentOS] Qlogic HBA scanning issues with CentOS 5.1 ?

[Finnur Örn Guðmundsson]

Hi,

I got few servers (IBM HS20,HS21 blades, IBM xSeries 3650 & others) 
connected to a dual fabric san throught Qlogic HBA's (23xx, 24xx). 
Multipathing is done with device-mapper-multipath.


On CentOS 4.x i can scan for new scsi devices without any problems, get 
them up with multipathing & use them without any problems.


However, after i started installing CentOS 5.1 (did not notice this 
problem with CentOS 5) i cannot seem to rescan without huge problems. 
Sometimes when i rescan after presenting a new LUN to the server nothing 
is detected, and sometimes the device comes in without any problems at 
all. Sometimes i even loose some paths after rescanning.again, i had 
no problems at all with CentOS 4.x.


I use the Qlogic script (Dynamic Target and LUN Discovery 
 
2.2) to scan for new luns.


Has anyone had any issues with scanning for new devices off san after 
upgrading to 5.1 ?


Thanks,
Finnur
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