Entware and USB Storage

[Denna]

Every article I've read about installing Entware on a router (Asus RT-AC88U) states an external USB drive should be used.

Does it matter what type of flash drive should be used ?

How much I/O does Entware generate with a flash drive ?

Currently, unbound is the only application that would be installed with Entware.

 

[Zirescu]

Probably want to go with EXT2 - you don't want journaling on a a flash drive.

 

[RMerlin]

Generated I/O will greatly depend on what Entware packages you install. If you only install some shell utilities then there will be zero I/O generated. however installing lighttpd or any other service that does any kind of logging will generate I/O according to the service installed.

A DNS server should mostly generate I/O on logging, the rest is usually cached in RAM.

 

[Denna]

But what type of drive should be used ?

Like a USB 2.0 drive or a low cost SSD ?

 

[RMerlin]

But what type of drive should be used ?

Like a USB 2.0 drive or a low cost SSD ?

Any regular USB drive. Go with a well-known brand, rather than freebies or discount-bin thumbdrives. I would avoid using an SSD, since it would be limited in speed by the USB port, and lack of TRIM support on the router might cause more performance issues down the road.

 

[sfx2000]

Probably want to go with EXT2 - you don't want journaling on a a flash drive.

EXT3...

EXT4 is better, but yes, there's the journal...

Big enough drive though, and that doesn't matter... (bigger drives have wear leveling and other nice stuff courtesy of the controller on the drive itself)

 

[sfx2000]

Any regular USB drive. Go with a well-known brand, rather than freebies or discount-bin thumbdrives. I would avoid using an SSD, since it would be limited in speed by the USB port, and lack of TRIM support on the router might cause more performance issues down the road.

Newer kernel would be nice, but flash/ssd support has been in since the 2.6.30 kernel, so one can always do the noatime/relatime switch in the fstab for devices hard mounted to reduce some impact to the filesystem and devices...

If I recall - the 3.2 and later kernels - true trim support there, but not likely for AsusWRT as it stands at the present (Jan 2017)

I agree though - but for different reasons - basically the 4708/4709 can't push the USB bus hard enough/fast enough to benefit SSD's - so a spinner is best here within reason (no monster drives, there is a FS size limit, which if I recall is 4GB)

 

[Zirescu]

EXT3 also has journaling.

 

[RMerlin]

It's often recommended not to use a journal on a USB thumb drive due to the added overhead (USB performance being already pretty bad on these routers) and the added wear on the USB device's flash chips.

 

[Denna]

So a 64 GB drive should be plenty ?

How about this one ?

Samsung 64GB USB 3.0 Flash Drive Fit

https://www.amazon.com/dp/B013CCTNKU/?tag=snbforums-20​

 

[RMerlin]

So a 64 GB drive should be plenty ?

Depends on what you intend to use it for. Here, I only have an old 4 GB Kingston flash drive connected to the router - it's enough to store the small Entware packages that I might need, and a few test files.

 

[Zirescu]

Might want to go with a longer key to make it easier to remove the drive from the router when it's time to do firmware updates.