Low memory problem

Hi All,

The rootfs on my target is present on the ramdisk, but the memory of my target is very low (64M). Now, when I FTP to my target and try to copy a new file to it, the total free memory gets used up, and my target becomes non-responsive and restarts after few seconds.
The users for my target use WinSCP to copy files to it.

Is there any way so that I can restrict the FTP transfer if there is less memory on my board?

Thanks in advance,
Mantis

Is there another storage except RAM, such as flash, on your target?

Hi nini,

Thanks for the reply.

Yes, there is a compact flash for permanent storage on my board. But the problem is, the files have to be copied to /tmp on my target which is a tmpfs.

Mantis

If you platform supports it, you could try to setup quotas: http://www.yolinux.com/TUTORIALS/Lin...ialQuotas.html.

If the quota is exceeded the FTP server should return 553 Disk full - please upload later.

Hi cnxsoft,

I could use disk and memory quotas for my users but I think I may face the following problem - Any user of the admin group and start an ftp upload into tmpfs. So, if I have set the memory quota for each user to be (say) 8M, and I'm already running low on memory (<4M for eg), a new user of the same group can login at this point and start the upload, thinking he still can use 8M of the physical memory.

Or is it that, if the minimum quota allocated for a user is not present, he will be denied login?

If your new file is very big, it is better to save in flash instead of ramdisk. FTP can save file in anywhere you want. The tmpfs is for small and temporary file.

Hi PrayingMantis,

I'm not sure about the details, I just gave some ideas, you'd have to try if you want to use quotas. Another solution could be to modify the code of your FTP server (or should I say ssh daemon since your users use winscp) to prevent the issue, e.g. check the free space + size of current downloads before starting downloading a new file.

Having said that, mini09 is right: it's a probably better idea to save your files in flash instead.

The only reason to do what you want to do would be to have another binary program which looks for files in /tmp.