I have a bit of an odd situation I would like to float out here and see if anyone has any ideas on this..
We are working on doing Disaster Recovery on a number of RHEL 7.4 systems. These are running on Cisco Blade Servers.
The mount point for /boot is on a Multipathed SAN LUN. There are a couple of other SAN volumes as well in disk groups; none of those are being problematic, but /boot is.
Above is the mount for the production system. We use SRDF to copy this data to a DR site and then clone the storage and boot up the same hardware at the DR site; Cisco blade servers (same models) as in production.
When we boot up the DR nodes, the system understandably gets a little 'confused' and will mount /boot to a RAW device.
Note /dev/sd* instead of the MPATH device /dev/mapper/***
So to fix this:
First, I run a 'multipath -W' and this corrects the extra WWIDs in /etc/multipath/wwids file.
Now the WWIDS from the production side are gone and only the new ones that are at the DR site exist - So that file is now a happy file.
After that, I need to add a filter to /etc/lvm/lvm.conf to ignore any devices aside from the /dev/mapper devices (RedHat support suggested that I add the global_filter as well - but it seemed to work ok with just 'filter', but it didn't hurt either..
Then - create a new initramfs image:
And reboot.
The server comes back up in either rescue or emergency mode (I'll pay more attention next time) and EACH TIME, running grub2-mkconfig fixes it - and the server boots just fine.
I need to figure out what's going on for my own geeky-obsessive-ness. The thing is, I saved a backup copy of /boot/grub2/grub.cfg and compared it to the new one that was generated in emergency mode and there are zero differences. I used notepad ++ and did a file comparison - even adding a character to verify the plug-in was working right and I can find no difference at all between the two files.
I thought that grub2-mkconfig just generated a new grub.cfg file, but it almost seems like something else is going on here as well.
Any ideas?
It's not that I can't get these servers back online, it's just that I would like to skip the reboot into rescue mode - as we are looking to automate this process as much as possible.
We have recovered these 4 nodes a couple of times - this process seems consistent. I just can't figure out what change grub2-mkconfig is making to the system to get it to boot!
I have solaris 10 sparc. I installed a Qlogic hba card.
This card is connected on a brocade switch and the brocade is connected on 2 different controllers on a Hitachi disk bay.
I formated 2 luns. On my solaris system, i have 4 disk.
How to configure solaris 10 to fix the dual disk view.
... (4 Replies)
Hi,
I saw your post on the forums about how to setup IP multipathing. I wanted your help on the below situation .
I have 2 servers A and B . Now they should be connected to 2 network switches . S1 and S2.
Now is it possible to have IP Multipathing on each of the servers as follows ?
... (0 Replies)
Hai
we using emc storage which is conneted to M5000 through san switch.
we asign 13 luns but in server it is showing 22 luns.
i enable the solaris multipathing (MPxIO)
#more /kernel/drv/fp.conf in that file
MPxio-disable=no
#mpathadm list lu
it shows ... (2 Replies)
Hello,
I turned on the server multipathing:
# uname -a
SunOS caiman 5.10 Generic_141444-09 sun4v sparc SUNW,T5140
stmsboot -D fp -e
And after a reboot the server, multipathing is not enable:
# stmsboot -L
stmsboot: MPxIO is not enabled
stmsboot: MPxIO disabled
# ls /dev/dsk... (4 Replies)
Hello,
I'm trying to put puppy linux 4.2.1 (I can't use the latest because it won't boot on my hardware) on a grub2'd usb drive.
It throws the error that it can't find pup_421.sfs
Here is my /boot/grub/grub.cfg
menuentry "Puppy 4.2.1" {
loopback loop... (2 Replies)
Hello, firstly excuse for my poor english.
I have a busybox error when I try to run Debian 6. It's like Grub cannot find root (initramfs)
My system is:
- RAID0 with dmraid
- /boot ext2 (from moonOS installation --ubuntu based--)
- ext4 (moonOS wich have the Grub2 installation, where I... (0 Replies)
I got a dual boot with grub2, but everytime I turn on the computer and the booter is loaded, I can't handle the menu, so I am forced to wait the countdown and choose the default option.
I'd really like to know why!
This is my grub.cfg,
# # DO NOT EDIT THIS FILE # # It is automatically... (0 Replies)
Hello
This is happening on: 3.13.7-200.fc20.x86_64
This happened already some weeks ago, until now i didn install linunx onto this machine, as i had to turn in the laptop to the service center so they could fix the UEFI flash storage.
Either way, its happening again. as i installed Fedora 20... (1 Reply)
I have a couple of questions regarding multipath.
If I do vgdisplay vg01, I see it is using 1 PV: /dev/dm-13
If I type multipath -ll I see dm-9, dm-10, dm-11, dm-12, but do not see dm-13. Is my vg01 multipathed? How can I actually know for sure?
Secondly, let's say this time vg01 says... (1 Reply)
I have centos 7 gui installed on vmware workstation12 on my laptop.WhenI want to pause my splash screen while starting my centos 7 using the 'esc key' nothing happens and the system just boots up.I also see a entry for aci_memory_fail... entry during the boot process.help me fix the system. (1 Reply)