MicroSD as cache possible?

[mace]

I'm moving Unraid to my HP Gen8 Microserver and wondered if it's wise to use the MicroSD slot on the board as a cache disk?

I boot off USB and will be using the ODD bay for a 2.5" data disk if I can config this way.

I've installed a 32Gb class10 card and Unraid 6.2 sees it and will allow me to add it if I choose (I assume), but lets say I get a 128Gb MicroSD card and assign it to cache, rather than take up a sata channel. (128Gb is big enough for my cache needs)

I've searched but haven't seen anyone else comment they've done it, but I did see a post about the SD card becoming unusable if power suddenly removed from the server, put down to a bios fault which a UPS would cure).

 

So, can it be done and should it be done?

Any tales of success or disaster?

Cheers

 

[itimpi]

(micro) SD cards have a very limited number of read-write cycles before they can be expected to fail (much less than a SSD).  They also tend to have limited write performance.    On that basis even if it could be made to work I would not think this would be a suitable device to use as a cache drive.