The above URLs are for $15 devices that allow connecting a SD card to an IDE bus or a CF card to a SATA bus.

http://etbe.coker.com.au/2008/01/24/ide-dma-and-flash/

I’ve used a card similar to the IDE to SD one before and had some issues with it (documented at the above URL). Also performance was lower than I expected (although adequate for the purpose of the machine).

The CF to SATA device might be OK, but would use a precious SATA port.

Raymond: That’s interesting to know. At the moment I have no plans to buy Dell rack-mount servers so it’s only a matter of curiosity. If Dell starts doing such things in their tower servers then I’ll be interested (I expect to deploy a few of them in the near future).

Les: I have heard some bad reports about the reliability of USB for a long-term connection. Apparently USB is good for what it’s designed for (rugged external connections) but not so good if you want to replace Ethernet or anything else that has semi-permanent connections. Also I’m very concerned about the reliability of external parts, too many idiots gain access to server rooms.

Pants: Solid state storage has vastly different failure modes to moving storage, and thus different methods can be used to protect it. So if you were paranoid you could have the data stored twice on the same flash module (failure of an entire module is a lot less likely than failure of an entire hard disk).

Flash has been used for the BIOS on most motherboards for more than 10 years. It seems that motherboard failure is pretty rare, I’ve got a bunch of broken hard drives from machines I maintain, a heap of machines with broken PSUs, while motherboard problems are very rare. Of the small number of failed motherboards, most of them seem related to cracks from inserting expansion cards. Also for a lot of consumer electronics gear (mobile phones, PDAs, Netbooks, and probably TVs and VCRs) you have flash soldered on to the motherboard. The reliability of such devices seems at least equal to that of PCs.

Matt: Long term storage of USB attached hard disks should be pretty good. Long term storage on cheap USB flash devices is probably a bad idea. I don’t know of any good research on this matter, but I have noticed that on a quiet day at your local electronics store you can ask the staff which brands of USB device tend to be returned and which don’t. With some brands it seems common for them to lose data before the customer loses the receipt.

there is still too short a lifespan for flash to be reliable enough to use as primary OS storage too.

plus, its better to use iscsi or a SAN to provide storage to servers these days. i think its time to move away from internal storage.

I don’t know if the standard build includes the PCI riser with SD slots, but it would only take a quick call to Dell to confirm. I’m unable to recall the cost of having ESXi pre-installed; however, it was not very much as ESXi is now free. Worst-case scenario, you could order it with ESXi & then install the OS of your choosing on the SD card.

Regarding power and cooling, the boxes seem to run very cool & quiet, but we’ve not put them under great load yet. They are AMD-based & don’t use FB-DIMMs, so they are less power-hungry than Intel-based systems (in my experience).

But, if the server is not storage constrained (that is, you have a free SATA port), why not consider a SATA DOM (disk on module)? Search for Sata DOM or SATADOM.

I have seen 4GB for $100-250, but I am not sure what causes the price range.

Cheers,

JP