does anybody has any experience configuring kdump on servers running with HDLM ? It seems that kdump service uses mkdumprd
and to use dlmmkinitrd I would need to hack "kdump" script.
Any experience in this topic ?
Modify fstab and grub to reflect a single block SCSI device (I prefer UUIDs over labels or /dev/block devices names) instead of using a pseudo device. More steps might be required depending on your configuration (dracut, encryption, etc).
I really wish I had time to test this in the labe because from a Linux perspective, it should work. I just think it's not supported because it's not tested.
Hmm, no experience at all ?
Are you using boot from SAN?
Yes, I am.
I haven't tried it, but I don't think booting from a dlm pseudo device is supported at all. I guess you could boot from a static SCSI block device and not worry about dlmmkinitrd. Of course this means you won't get HA for the boot device... Sounds like an interesting experiment.
I know SAN boot with HDLM is supported and I've set it numerous times without any issues. But never worked with kdump and HDLM before. The manual has only a small mention on it:
"If you use the kdump function in an environment where an HDLM device is used as a boot disk, you might need to create an initial RAM disk image file for kdump in a single-path boot disk environment that uses a SCSI device."
That's pretty much what I expected. As soon as you start to do anything fancy (like kdump, encryption, zfs, etc) things tend to go south from a support perspective. I was onsite doing some Linux work a few weeks ago (boot from SAN multipathing issues) and redhat support recommended changing our configuration to boot from a UUID or label (which of course points to a static block device after udev processing).
That said, this kdump question does have me interested. In theory if initramfs (the ram disk) is correctly configured or dracut has been used to generate it from a live system and all the correct modules are pulled in, I don't see why it wouldn't work.
Hmm, this sentence ("If you use the kdump function in an environment ...") is IMHO not enough.
It would be good to add at least a few hints how to do it.
Hi Przemyslaw Bak,
Have you been able to set this up? Please let us know - thanks.
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