Suitability of legacy 12-bay rack-mount ReadyNAS units for home use
I have begun to see some of the large legacy ReadyNAS 2U rack mount units (3200, 4200, 4200V2) for sale at some pretty low prices. Like myself, others may be tempted to buy one for home use. So, I thought I would write a review of sorts, dealing only with the aspects of these units that are different from the legacy desktop models. Some of this may apply to the 1U rack mount units as well, but I don't have one to say what does.
Like all X86 based legacy units, these units shipped with RAIDiator 4.2.x, which is quite dated. But like the desktop systems, the 64-bit systems (which includes all 12-bay systems) can be upgraded to ReadyNAS OS 6.x, though that is officially unsupported by Netgear. While I have done this, most of the items below are independent of the OS.
First of all, these machines are big -- 19"W x 3.5"T x 27"D (excluding space for cabling and exhaust in the rear). And they are ugly, clearly designed to have all but the front obscured by a rack. Make sure you have a place to put it.
Next, they are loud. Three chassis fans and 2 redundent power supply fans make plenty of noise, even when idle. The power supply fans are especially annoying, as they are small and high pitched. On mine, the frequencies of the two are about 30Hz apart, so there is a constant 30Hz "warble" caused by the beat frequency between them. And the power supply fans stay on even when the unit is off, drawing about 20W. If you upgrade a 4200V2 to OS 6.x, it's even louder until you make a change to the fan control via SSH (mine got up to 6000+ RPM at idle and sounded like it was ready to take off). A closed rack would certainly tame the noise some, but that adds cost.
The 3200 and 4200 support drives of 2TB max, the 4200V2 supports bigger ones. It's a motherboard limit, so no work around. Note that a 4200V2 is clearly labeled as such on the ID label. If it doesn't say "V2", it isn't. (I do know some of he 1U units also have this limitation, and some of them are also 32-bit and can't run OS6.x.)
A 12 drive single volume will be difficult to recover if something happens to the chassis/motherboard and you don't have another 12-bay system to put the drives in. A work-around to this is to have multiple volumes where each has no more drives than the largest other system you have with the same OS. I have run experiments (under OS 6.x, but I have no reason to believe the results would be different if you stick with 4.2.x), and you can divide the array into two 6-drive volumes and then put either set of 6 into a 6-bay system and recover the data. Of course, you should always have a backup, anyway; but it's nice to know. Depending on drive sizes, two 6-drive volumes with single redundancy may give you more drive space than a single 12-drive volume with dual redundancy (you really didn't expect to have single redundancy on a 12-drive array, did you?). But dividing into multiple volumes carries some baggage. You have to decide which shares go on which volumes -- shares can't bridge all drives (that's the point for recoverability) -- and you cannot use the expandability of XRAID2.
These systems have a single CPU, but the 4200V1 & V2 with their quad-core Xeons should be able to be a decent media server. There is lots of room for more RAM, and they use ECC server RAM, which tends to be cheaper these days than non-ECC. The 3200 and 4200V1 use DDR2 and the 4200V2 uses DDR3.
The chassis is a standard Supermicro one. Caddies are readily available, as are replacement fans and power supplies. Fans and power supplies are designed for easy replacement. The motherboards are custom versions of Supermicro ones, and standard ones may or may not work. The Netgear version is lacking some functions and parts, and has a custom BIOS to match, so the standard could work out of the box if the OS doesn't check the BIOS version. Or, you might need to flash it with the Netgear BIOS. The 3200 BIOS is in the BIOS_Update_Package_0.5-x86.bin, but the 4200's and 4200V2's are not. The OS boot flash is a USB device plugged into the motherboard, so it could be moved to another motherboard. It carries with it your serial number.
In case you are thinking it, I don't think the 3200 and 4200V1 can economically be upgraded to a 4200V2 with just a motherboard swap, even assuming the standard Supermicro version would work. The motherboards have identical footprints, but the SATA cabling is different. You'd need the back panel filler for the new motherboard, too; but that normally comes with it. I haven't seen enough pictures of the SATA backplane of a 3200 or 4200V1 to know if it will work with the X8SI6 motherboard of the 4200V2 and the right cabling. And I really have no idea if the USB flash from one type would boot the other, but suspect it wouldn't work well. In the end, you'd likely pay more than for a 4200V2.
Re: Suitability of legacy 12-bay rack-mount ReadyNAS units for home use
OK, after some more experimenting, it seems you are not completely wihtout XRAID expandability, at least on OS6.x. I have two volumes and ran the following experiment on both:
Powered off. Removed drives that made up the other array. Powered on. Toggled on XRAID. Expanded RAID with another drive. Toggled off XRAID. Powered off. Returned other drives. Powered on.
I got different results depending on the array expanded.
When I expanded the main "data" array from 4 to 5 drives, everything just worked when I put the other drives back in.
When I expanded my second array (which I call "test") from 1 drive JBOD to 2 drive RAID1, it warned me of "dirty disks" in RAIDar and wouldn't boot when all drives were back in. I did a lot of experiments, and ultimately got it booted with both arrays intact, but I'm not sure which thing I did made the difference. I think it might have been booting without the second array, then adding those drives "hot". At that point, it recognized the array, but there was a red dot by it on the Volumes tab instead of the normal green one, which I think meant "offline". After I did that and re-booted, everything was recognized and online. But I also booted the system once with each array individually (to see that they were still intact after the hot add) before putting it all back together again. So that may have had a effect as well. I plan on doing this again and see if I can figure out what made it work.
Now, taking a volume offline to expand it kinda defeats the purpose of XRAID. And I have no idea just how safe this is. Using BTRFS tools to expand arrays via SSH is probably a better plan. But I've only begun to learn about that.
I don't see how this would work on RAIDiator 4.2.x, because you can't toggle XRAID off and on.
Re: Suitability of legacy 12-bay rack-mount ReadyNAS units for home use
After more experiments, I can say that this is not a reliable method to expand a dual-volume system. It still worked on the primary volume, but nothing could mount the secondary. And I wouldn't trust that the primary will always survive,
Re: Suitability of legacy 12-bay rack-mount ReadyNAS units for home use
I've been running my 4200V2 for a while now, so I thought I'd add to this review.
As for the XRAID expandability with multiple volumes -- definately a no-go. I guess I just got lucky once. I tried it several times, and never succeeded a second time. And I was done doing all the factory defaults and experiments and wanted to let it run a while. FlexRAID is still expandable, just not with as many options for mixing drive sizes as XRAID.
I have my 4200V2 in a spare room in my Florida home that has the A/C vent closed. It recently hit 89F outside and was in the 90's in that room. Still, the drives in the 4200 were running cooler than the drives in my Pro6 in the air conditioned computer room kept at 75F. I guess that wind tunnel created by the fans is there for a reason. How much the 4200 aided in the room temp reaching into the 90's, I can't say. But I'm sure it contributed. Ultimately, I plan this to be a backup unit that powers on periodically, but I wanted to see how hot it would run. So far, it looks good.
Oh, and I did mis-speak about the 4200V1. 4 of the drive slots on it can handle drives larger than 2TB. It's at least some consolation.
