[Tip] FS-Manipulation in 7.1.3-Clusters


Login or Register for Dates, Times and to Reply

 
Thread Tools Search this Thread
Operating Systems AIX [Tip] FS-Manipulation in 7.1.3-Clusters
# 1  
[Tip] FS-Manipulation in 7.1.3-Clusters

In principle it is possible to create FSes on shared volume groups with cluster methods (also known as C-SPOC), either from the command line or using the respective SMIT menus. In practice, however, many options are missing in the C-SPOC variants. For instance, it is not possible to add a mountgroup to a newly created FS.

Many (me included) rely therefore on non-cluster methods (the normal crfs-command, et. al.) even in cluster environments. One common method, using the non-documented command imfs, is like this (we are supposing a two-node active/passive-cluster here):

Code:
root@activenode # crfs ....
root@passivenode # varyonvg -ncA <sharedvg>
root@passivenode # imfs <sharedvg>
root@passivenode # varyonvg -ncP <sharedvg>

This will not work any more with HACMP 7.1.3 upwards because IBM introduced a new (and very badly documented) fencing mechanism. If you try the above on a newer cluster you will immediately find the disks in <sharedvg> in the errpt as missing. The only method to get clear from this is to cycle the cluster completely.

Instead use the following method now:

Code:
root@activenode # crfs ....
root@passivenode # /usr/es/sbin/cluster/events/utils/cl_set_vg_fence_height -c <sharedvg> rw
root@passivenode # varyonvg -ncA <sharedvg>
root@passivenode # imfs <sharedvg>
root@passivenode # varyonvg -ncP <sharedvg>
root@passivenode #  /usr/es/sbin/cluster/events/utils/cl_set_vg_fence_height -c <sharedvg> ro

If you want to try the - old and new - method use a cluster you can afford to powercycle. There, you will be able to watch the problem unfold in hacmp.out - or the C-SPOC log, if you have used it.

I hope this helps.

bakunin
________________________
Sources:
This User Gave Thanks to bakunin For This Post:
# 2  
# 3  
@agent.kgb, when providing a link please also describe what we can expect to find there, preferably by quoting the relevant part.

After reading that page, I gather what you mean to say is that imfs is in fact documented.
# 4  
Quote:
Originally Posted by Scrutinizer
After reading that page, I gather what you mean to say is that imfs is in fact documented.
To be honest, i haven't seen that part of the LVM redbook (or maybe i have but couldn't remember). Fact is that there is no man page for the command, it is not mentioned in IBMs online documentation and - save for the passing quote agent.kgb found - nowhere else in IBMs documents.

Even the redbook is very terse about it. A half-sentence hardly qualifies for "documentation".

Alas, this is similar to some other parts of the OS, which are also very poorly (or not at all) documented: mkinstallp, pre-7.1 HACMP cluster-commands and so on.

bakunin
# 5  
bakunin is right. The command imfs is not documented. The redbook is the only documentation about a lot of intermediate-level LVM commands and it is very outdated. There are some other undocumented and very useful commands in the redbook, such as ipl_varyon, getlvodm or lvlstmajor. IBM doesn't like if you know too much about AIX internals ;-)

Last edited by agent.kgb; 08-18-2015 at 05:20 AM..
# 6  
Quote:
Originally Posted by agent.kgb
bakunin is right. The command imfs is not documented. The redbook is the only documentation about a lot of intermediate-level LVM commands and it is very outdated. There are some other undocumented and very useful commands in the redbook, such as ipl_varyon, getlvodm or lvlstmajor. IBM doesn't like if you know too much about AIX internals ;-)
This is absolutely true!

It might be a worthwile community project to write documentation for these undocumented commands. getlvodm, for instance, i have used literally for decades now (it must have been introduced in AIX 4.1.x or so). Anybody interested?

bakunin

@Scrutinizer: i took agent.kgbs link as a rather witty comeback regarding my use of the word "undocumented". No harm done. ;-))
# 7  
do you have a spare domain? ;-) I have some spare servers.
Login or Register for Dates, Times and to Reply

Previous Thread | Next Thread
Thread Tools Search this Thread
Search this Thread:
Advanced Search

Test Your Knowledge in Computers #352
Difficulty: Easy
Unix was created 25 years before Linux.
True or False?

8 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

Getting unique based on clusters

Hi, I have a file with 25 clusters and each cluster has multiple rows. I need to find the unique genes in each cluster and assign them Annotation Cluster 2 Enrichment Score: 10.199579524507685 Category Term Count % PValue Genes List Total Pop Hits Pop Total Fold... (1 Reply)
Discussion started by: Diya123
1 Replies

2. Red Hat

How to configure redhat clusters on VMWARE?

I'm using redhat 5.1 installed on VMware work station9. Can you guys help me to configure redhat clusters. (1 Reply)
Discussion started by: karthik9358
1 Replies

3. High Performance Computing

I/O bound computing clusters

I want to build a computing cluster and have been looking into grid solutions. My understanding from grid solutions is that participating nodes have to actually sign up to participate in a computation and that an isolated piece of work is sent to the node through a request from that node (pull).... (4 Replies)
Discussion started by: figaro
4 Replies

4. Solaris

VCS Clusters

:)Hi, can someone please explain VCS clustering and where do we need VCS clusters ..? :o:)Thanks in advance :o:) (1 Reply)
Discussion started by: amitbisht9
1 Replies

5. Solaris

jumpstart install clusters

Hello, I'm trying to jumpstart a machine with Solaris 10, however the disks in my machine are only 18GB, but I want to have all the developer packages but none of the X windows stuff that can be quite large. Wondered if it was possible to somehow get a list of all packages and remove the ones... (4 Replies)
Discussion started by: Actuator
4 Replies

6. Solaris

meaning of states in sun clusters

Hi Everybody, As I am new to Sun Clusters, Please help me what is "online but not monitored" state of resources and "online - service is online" in status message. Thank you. (1 Reply)
Discussion started by: mayahari
1 Replies

7. Solaris

about Solaris Patch Clusters md5sum

Hi, for Solaris Patch Clusters version 10_x86_Recommended.zip (Jul 15 2009 / 817 MB - SunSolve) MD5: be40488b0fb1d081deda69dbca415be3 is correct? (the problem is that I don't have an account. ...therefore I can't login on Sunsolve for view MD5 page) yes, is a terrible thread! ... (3 Replies)
Discussion started by: gxmsgx
3 Replies

8. High Performance Computing

question about clusters

hello all...first off let me say hi and im really glad to be apart of this community....tried to join awhile back but i couldnt for some reason im a highschool student and im eager to learn and what im trying to learn now is clusters i have 3 computers in my room all connected on a simple hub ... (1 Reply)
Discussion started by: hexadecimal0011
1 Replies

Featured Tech Videos