I have an arch install with the root partition on a flash drive. Additionally, I have an external hard drive which has my HOME and SWAP partitions on it.  I have read online that using a flash drive for swap can prematurely wear out a flash drive, is this also the case for the OS install? Is there any advantages/disadvantages of moving my root partition to the HDD or can flash drives be used for a more long term time from to store and OS?
Can linux be run on a flash drive long term
partition;hard disk;flash memory
Flash drives are based on flash memory which has a limited number of write-erase cycles. See https://en.wikipedia.org/wiki/Flash_memory#Memory_wearHowever, I believe this is less of a problem with modern flash memory.Most Linux distributions follow the Filesystem Hierarchy Standard (FHS, https://en.wikipedia.org/wiki/Filesystem_Hierarchy_Standard). If you read through the descriptions you can see that /var is used for variable data. Variable data, as the name states, changes often and therefore causes lots of writes to the storage device. To reduce wear on your flash drive you should move /var to a separate storage device.Depending on the amount of memory your computer has you could also consider disabling swapping. This can be done using the swapoff command.You may be interested in reading the following pages on the Arch Wiki:Installing Arch Linux on a USB key: https://wiki.archlinux.org/index.php/Installing_Arch_Linux_on_a_USB_keyandImproving performance (section about reducing disk read/writes): https://wiki.archlinux.org/index.php/Improving_performance#Reduce_disk_reads.2FwritesI have been running an Arch Linux installation on a cheap Kingston flash drive for a little over two years now without a problem, without any extra storage!