The thing that I couldn't quite get past in the meeting was that the procedure for them to move from storage on one section of the SAN to another was as follows:
This gambit works successfully when the person the vendor is talking to is a manager or otherwise unfamiliar with the way Linux is developed. I at least pointed out that these drivers that they were complaining about were open source - they were freely available for the vendor to modify to support their esoteric requirements. At this the vendor's people shrugged and said that there was nothing they could do about this - which is true but useless. I don't know the details of how these things are constructed, so I really can't say how fiber-channel cards see their SANs or whether they can actually support hot-plug or not, so I can't really tell them source file and line to tell them otherwise. I know that SCSI wasn't designed for hot-plug, but then why is it using the SCSI bus if the devices support hot-plug? I don't know.
While I have been rebooting and waiting and rebooting on these servers for these devices to show up, I have meanwhile plugged a hard disk into my work machine, added its space to my main volume group, moved all the data off my old disk, reformatted the old disk, repartitioned it, put the /boot partition back and moved all the data back using LVM commands while the system was running. I thought I'd have to reboot at one point, but it turned out I still had /boot mounted and once I unmounted it I could rescan the partition table successfully. No reboots, no obscure proprietary binaries, no tainted kernels, no mysterious handwaves, nothing - just solid performance. And this is on commodity hardware! What is wrong with these people?
Oh, and in case you're wondering which vendor, there's a subtle clue somewhere in this document.
All posts licensed under the CC-BY-NC license. Author Paul Wayper.