Unable to find some place from which I can get service and a legit download of the necessary firmware (even from a questionable site), I've decided to order a couple of the smaller supported drives to get the box working.

The specs and articles available now show that the Sun Fire X4600 M2 can support 300GB SAS drives. Anecdotally, my Sun Enterprise T5220 has 6x300GB drives in it (and 2x146GB drives as its OS RAID pair). Because of this, when I purchased the diskless server, I also got a pair of 300GB drives. It seems now, however, that much of those articles expected the machine to be updated to at least a one-version-newer-than-I-have version, which is about five versions behind when they stopped making firmware for it...in 2010. 

Small aside...don't the administrators of these machines keep them up-to-date? Plug 'em in and forget 'em? I guess maybe the 10-years-ago OS worked fine with the 12-years-ago firmware. Really thinking about it, I only very rarely updated the firmware on my workstations, and that was when Iw as trying to have cutting-edge video cards and needed the latest and fastest bus management. Still, as an aftermarket hobby consumer, I'd appreciate it if people who run these things would leverage their support contracts and keep the hardware as current as possible, firmware included...heh.

I'm a little bit leery that the drives are the problem, because the BIOS and disk management utilities both report a successful scan with no drives found. I'd expect if the drive were too big to address entirely that it'd give a misleading error, like the wrong size, or an accurate error indicating incompatibility. It may be that there's something still not completely default in the configuration. I mean, there's a PCI card in a slot that I haven't identified, but doesn't seem to be related to anything in the normal documentation; perhaps that's a storage card meant for some kind of SAN or other external enclosure, so the management isn't looking at the mainboard controller. I'm going to unplug it and see if that helps. At least to get a "I see the drives, but can't use them" kind of message. I mean, now I'm not getting a power indicator as the server cycles on; the other one flickers all of the lights on the drives as it looks for them ('though I have no empty drive bays so I'm not sure that they would...I would expect a little "nothing plugged in here" logic...has that everywhere else...).

Still, the drives are cheap, and in a worst case scenario, I'll have 2x300GB spares for my T5220. If the 146GB work in the X4600, I'm tempted to reconfigure the T5220 to have all 8x300GB drives, and put all 4x146GB into the X4600. Since the 146GB drives in the T5220 contain the OS, it would mean reconfiguring that server from the ground up. Looking back, I kept terse, scattered, indecipherable notes, or didn't keep notes at all...so that'd be an interesting re-learning. Right now that server is running the databases and a couple of Tomcat instances. Oh, and it has 1.8TB of storage, about 1.7TB of which is free... I guess even if the new drives don't work in the new server, I'll have those as spares for the T5220.

If the worst case happens, I'll have to look at options to run the server off of USB drives (eek!), or configure a PXE server and remote boot everything. The T5220 has loads of space, and they can be GB networked together. Since the X4600 has no storage (relatively speaking), I was going to use the disk space on the T5220 anyway. Running the OS that way is a little less desirable, but would be a different exercise.

This would take a totally different path with the later firmware on it.

I'm still concerned that even if I do get the 146GB to work, or figure out a USB or network boot, that I'll have firmware or BIOS related issues with the newer CentOS or Ubuntu, or even x86 Solaris.

This is the last such lesson I think I want to bother learning by getting older server equipment. I'm cloud savvy. The $400 the server has cost is a lot of time for cloud servers. At least for the level of things I am using them for. There are interesting articles I've found on how to spread the things out to different low-level free services. I don't have a lot of traffic (especially once you remove the intrusion scanning visitors and the SEO bots that look at my stuff all of the time (or give some small dollars to CloudFlare or other CDN, or change the way I make the site present so that more can be cached...).