Redundant storage on a single board computer

[shock_wave011]

Hey everyone, I am a little newer to single board computers and I am trying to do a project where I need to store a series of XML files on a single board computer. I want to mirror the data on to a second SD card. Does anyone have suggestions on hats for pi's/arduinos or if there is already a single board computer on the market with multiple SD card slots.

Thanks,

Shock

[jaslion]

You could just use a usb stick too.

[Levent]

You can set up raid1 with mdadm using atleast two usb drives but raid1 on a boot device is something I havent tried. I have a raid1 setup on my orangepi zero using two flash drives.

[mariushm]

Or you could use a high-ish capacity eeprom / flash chip with i2c / spi interface and make a backup there. How much space you need? You can buy chips up to a few MB in size in DIP packages, super simple to use and connect to a board ... and 16/32 MB flash chips are also very common and cheap (because they're basically the bios chips on motherboards)