I just use a 5M/512k ADSL with 1 client connected. When I use some p2p software. The router will cause 100% cpu usage in ‘FLASH’ when the memory is low. And after a mins, the router can not access by WinBox, sometimes will reboot automatically.
I have the support ticket #2013022766000852, but still no answer within one week!
I know the issue may be the memory is too small. Because I have set up 3600 route rules and about 40 firewall policies. When I use p2p software to download, the memory will become lower than 9MB, and than the process ‘FLASH’ casue 100% CPU usage. I think I need to replace with another model such as RB951G-2HnD with 128M RAM.
ROS’s memory usage is higher than TOMATO very much, the same settings was working fine in TOMATO 1.28~ 
Dear supporter,
I have sent the email and written the post at here for requesting my support, but why nobody help me? I think I just want to use ROS for policy route, vpn, pcq quene with my 5M ADSL at home. It’s the reason why I choice RouterBoard! If I only need the base service, I have too many better choice.
RB951-2n provide 26624 Max Entries. I just use 5M ADSL and about 300 entries, but the router halt and reboot. Is it too poor? Is it can run on 26624 entries??? I am mastery in TOMATO, DD-WRT, Open-WRT, m0n0Wall, PfSense, but I like ROS so much. RB951-2n is really too bad for me! It’s not the point, the point is I can not get help from MikroTik!
Flash process tells you that your router is doing some writing to flash memory. Are you using proxy or any other settings that use disk access?
I have nothing setting will cause the FLASH busy. Proxy was disabled. I think may be the memory too low and ROS use disk for virtual memory.
Hi!
I think may be there is something that usually gets cached in RAM, but in case RAM is running low it needs to be read from the flash.
Another theory is that you have a hardware issue, may be CPU is used by something else, but RouterOS interprets this as flash activity.
Anyway I think you should contact the seller about this problem.
Also, do you really have 3600 entries under /ip route rule ?
Deleted because not related.
Hi everybody,
Thanks for you all reply.
To: Dobby,
I have sent support email 2 days ago before this post and without any response.
Ok, I have replaced RB951-2n with a ZTX H618B which running TOMATO with 240MHz CPU and 32M RAM. It works fine with the same settings as 3600 route rules and 2 VPN tunnels.
And I want to tell you that books just can tell you the base knowledge. And if you just can read books you will never become an expert.
The example:
Mikrotik tell you RB951-2n is a home AP, and RB750UP is a router, right? I can tell you RB750UP with 32MB RAM only, my settings will not run normally on RB750UP too. And then, RB951-2n can accept 26624 max entries, I dont think a home AP need so more entries. If it limited to 8000 entries to save memory, it will become more useful.
I think you are right! ROS is base on Linux, it seems need about 9MB-10MB memory for caching. So if the free memory lower than 9MB, CPU will loading high with FLASH process.