Howto stabilize USB/SD rootfs

[bastibasti]

Hi,

Iam trying to install gentoo on an SD cardto be used as router. However in longterm tests I sometimes get io errors, which are gone after reboot.

Any idea what could be the reason for that? DO i need to activate any additional cache to minimite FS access?

I already mounted /var/tmp as tmpfs to reduce i/o load during emerge etc.

Any experience for that kind of environment? Filesystem to use etc?

[zeronullity]

Just all depends on your needs & target platform. I.E. - I run squashfs with tmpfs on a realtek 1186 chipset used to play/serve 1080p video.

Also depends on what sort i/o errors.. tmpfs running out of memory etc.

Is this a SOHO router.. like small retail router hardware?

[bastibasti]

its a dell d430

I never though about squashing root after finishing the setup. how do you manage updates / configuration changes? Do you have a script?

[zeronullity]

Squashfs.. consider it like a read-only archive changes need to be made to a external copy then compressed into squash format.
Any changes made to it's tmpfs on the target system will be lost upon reboot.. unless you have a separate FS to save changes. As far laptops go.. you have a lot of options usb drive, sata, there should be no need to use a squashfs. Just make sure you really need the extra cpu power.. as it can consume quiet a bit more energy then a standard router, depending how you have it setup.

[bastibasti]

Yeah,

When it comes to cpu power, it also handles surveilance cameras

but additionally you can buy the motherboards cheap as hell (I paid 30 bucks for 2) and power consumption on these D430 is apprx. 10W idle (ulv cpu), additionally i took away extra ram (the mobo itself has 510mb), keyboard, touchpad and wifi modules which should give me some more saving and if you need it, these board can compile a kernel, if you know what I mean.


Yeah I knew what squashfs was, I ve built my own gentoo based live usb before (squash+aufs) but for this setup i just never considered it

[zeronullity]

Well if your using it for video encoding I could see the need, if not then you could use a small router if it's for traffic only.
Although I believe using hardware/servers specific for the task.. it can save you a lot of headache in the long wrong.
If your only saving stills, no encoding, you might be able to use a small retail router for network only transactions & and then
another small router as a USB image recorder. In any case ext4 should be fine for some thing like this.. or ext2 if you want to save space.
You could even do software raid if you want backup, provided your using the laptop setup. As for USB thumb drives/SD media they don't really
make good live RW operating systems, compared to a standard sata/ssd drive they will fail much sooner under heavy reads/writes. However if you want to do backups, and don't care if you have any down time or cost associated with replacing the SD media later you can do w/e you want. =)
Just keep in mind of things like logging etc.. any thing that excessively writes to the SD media would be a bad idea.