Hello,
using Linux native multipathing (DM) I can name each device in config files and then refer to that names.
Is it possible to do the same using HDLM ? I need a consistent naming across servers and want
the same LDEV be named i.e. sddlma on all servers working in cluster.
How to do that using HDLM ?
Hi,
Persistent naming was introduced in HDLM v7.5. Here's the basic summary of the procedure:
1) Create a definition file: /opt/DynamicLinkManager/bin/dlmchname -o
2) The file will be at /etc/opt/DynamicLinkManager/dlmchname.conf. The content is similar to this:
3585011299 0090 sddlmac
3585011299 0091 sddlmab
3585011299 0092 sddlmaa
The columns are serial number, LDEV ID, and HDLM device name.
3) Modify the HDLM device names to whatever you want
4) Update HDLM using definition file: /opt/DynamicLinkManager/bin/dlmchname -f
5) Reset the server
6) Copy the definition file to other servers in the cluster and run steps 4 & 5.
Regards,
Dang Luong
Hi Dang,
thanks for your answer - this is what I was looking for !
I don't have any documentation at hand but is it described in the docs ?
If so in which manual ?
Search for the following document in the portal - MK-92DLM113-24, and page no starts from - 374
That's it - thank you :-)
I wonder why it is not mentioned in Release Notes for 7.5 - does anybody know ?
I am trying to test this feature and found some problems. The original file is:
10400086561 1901 sddlmaa
10400086561 1902 sddlmab
10400086561 1951 sddlmac
10400086561 1952 sddlmad
The new one:
10400086561 1901 sddlmaa
10400086561 1902 sddlmab
10400086561 1951 sddlmac
10400086561 1952 sddlmaz
And the error:
# dlmchname
KAPL12374-I This operation will change the HDLM device configuration. Do you want to continue? [y/n]:y
KAPL12394-E An HDLM device specified in the device name change definition file is invalid. HDLM device name = sddlmaz
KAPL12388-E The utility for changing HDLM device names ended abnormally.
Can anybody tell me why ?
are you trying to change the following line from 10400086561 1952 sddlmad to 10400086561 1952 sddlmaz. Please clarify.
If so you need to change the character "z" between "a" to "o" only. Rerun the command after doing the modification.
Please see the extract from the above said document. Pg 36-37
The logical device file name of an HDLM device has the following format:
/dev/sddlm[aa-pop][1-15]
About alphabetic letters used in the logical device file name:
¢ For the first 256 LUs, two alphabetic letters are assigned. The
specifiable values for the first two characters are in the range from a
to p.
¢ For the 257th and subsequent LUs, three alphabetic letters are
assigned. The specifiable values for the first and third characters are
in the range from a to p. The specifiable range of values for the
second character is from a to o.
¢ A major number is required for each of the first characters.
Yes, that is what I wanted to do.
Thanks for the documents - in seems that native linux multipathing doesn't have this limitation.
Hi,
Persistent naming was introduced in HDLM v7.5. Here's the basic summary of the procedure:
1) Create a definition file: /opt/DynamicLinkManager/bin/dlmchname -o
2) The file will be at /etc/opt/DynamicLinkManager/dlmchname.conf. The content is similar to this:
3585011299 0090 sddlmac
3585011299 0091 sddlmab
3585011299 0092 sddlmaa
The columns are serial number, LDEV ID, and HDLM device name.
3) Modify the HDLM device names to whatever you want
4) Update HDLM using definition file: /opt/DynamicLinkManager/bin/dlmchname -f
5) Reset the server
6) Copy the definition file to other servers in the cluster and run steps 4 & 5.
Regards,
Dang Luong