[CentOS-devel] Cent OS 5.5 Clustering and Support

[Tracy Reed]

On Fri, Apr 01, 2011 at 08:20:29PM +0530, Kumar, Ranjan spake thusly:
> We are a Channel product team within LSI and we are trying to add Cent OS 5.5

MegaCLI is completely unacceptable and the reason why I refuse to buy LSI.

As far as I can tell, the MegaCli package is the way to manage the Dell PERC
from the command line in Linux. To work with it you have to hunt down the
MegaCli-1.01.39-0.i386.rpm tools since the tools are proprietary to LSI and
don't ship with RHEL.

Then you RPM install it and go looking for the software it installed.  MegaCli
is rarely used. Only when setting up disks. They didn't call it megacli or
something I might remember. They called it MegaCli64 (case sensitive) which is
installed in /opt/MegaRAID/MegaCli/MegaCli64.

Then you have to figure out how to use it.

# /opt/MegaRAID/MegaCli/MegaCli64
Fatal error - Command Tool invoked with wrong parameters

hmm...ok

# /opt/MegaRAID/MegaCli/MegaCli64 --help
Invalid input at or near token -

hmmm

# /opt/MegaRAID/MegaCli/MegaCli64 -h

whoah! This gets you a massive amount of cryptic command line options with no
explanation as to their purpose. 

This is LSI's idea of "help". I'm a command line commando of 20+ years and this
scares even me! It would have been nice if they at least tried to make it work
somewhat like the Linux mdadm command or at least provided some examples of
common use cases etc. Because of the oddity of this command various people out
on the net have compiled "cheat sheets" to help poor souls like me figure out
how to use this thing:

http://tools.rapidsoft.de/perc/perc-cheat-sheet.pdf

Usually I avoid using this command and just reboot the server into the BIOS and
configure the RAID card from there but often it is not a convenient time for a
server reboot. I also avoid it because it is so complicated and one wrong
command can lose all of the data in the server. Yes there are backups, which I
would really rather not have to restore.

I needed to add a couple of disks on the fly and did not want to reboot. The
command line I seemed to need and response it gave me was:

# /opt/MegaRAID/MegaCli/MegaCli64 -CfgLdAdd -r0 [32:4] -a0
Adapter 0: Configured the adapter!!

Not a very reassuring response. Configured it how with what? It would be nice
if it said "Added virtual disk number 4 as a RAID 0" since that is what that
command told it to do.

Using the command:

/opt/MegaRAID/MegaCli/MegaCli -LDInfo -Lall -aALL

I was able to verify that it had in fact created virtual disk number 4 as a
RAID 0. However, I didn't have a file to work with in /dev representing the
disk. The operating system simply refused to see the disk so that I could
actually do something with it. I spent some time trying to figure out why but
couldn't come up with a solution. Eventually I just had to reboot and my whole
investment in hot-swap chassis and RAID card went out the window.

-- 
Tracy Reed
http://tracyreed.org
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