On 10/14/2011 5:49 AM, Darren J Moffat wrote:
On 10/14/11 13:39, Jim Klimov wrote:
Hello, I was asked if the CF port in Thumpers can be accessed by the OS?
In particular, would it be a good idea to use a modern 600x CF card
(some reliable one intended for professional photography) as an L2ARC
device using this port?

I don't know about the Thumpers internal CF slot.

I can say I have tried using a fast (at the time, this was about 3 years ago) CF card via a CF to IDE adaptor before and it turned out to be a really bad idea because the spinning rust disk (which was SATA) was actually faster to access. Same went for USB to CF adaptors at the time too.

Last I'd checked, the CF port was fully functional.

However, I'd not use it as L2ARC (and, certainly not ZIL). CF is not good in terms of either random write or read - professional-grade CF cards are optimized for STREAMING write - that is, the ability to write a big-ass JPG or BMP or TIFF as quickly as possible. The CF controller isn't good on lots of little read/write ops.

In Casper's case, the CF->IDE adapter makes this even worse, since IDE is spectacularly bad at IOPS.

I can't remember - does the X4500 have any extra SATA ports free on the motherboard? And, does it have any extra HD power connectors?


Is a great way to add a 2.5" drive slot, but it's just a physical slot adapter - you need to attach a standard SATA cable and HD power connector to it.

If that's not an option, find yourself a cheap PCI-E adapter with eSATA ports on it, then use an external HD enclosure with eSATA for a small SSD.

As a last resort, remove one of the 3.5" SATA drives, and put in an SSD in a 2.5"->3.5" converter enclosure.

Remember, you can generally get by fine with a lower-end SSD as L2ARC, so a 60GB SSD should be $100 or less.


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