How many writes to flash will kill it?

RouterOS General
1

How many (aproximately) writes to flash will kill it?

I have:

[admin@TESTY] > /system resource print
uptime: 4d20h48m45s
version: “2.9.25”
free-memory: 15744kB
total-memory: 30440kB
cpu: “MIPS 4Kc V0.10”
cpu-frequency: 264MHz
cpu-load: 0
free-hdd-space: 93816kB
total-hdd-space: 126976kB
write-sect-since-reboot: 34491
write-sect-total: 103900
bad-blocks: 1

Should I worry about last two numbers? Is 100.000 written sector really big value? Should I consider changing config & preparing new flash with backup?

Gregor

2

that is writes per card, flash can be killed by some hundeds of thousands writes per sector. no worries, we have not seen one dead flash for years. at least not dead by writes.

3

by the way, that’s a RB500, you can’t change the flash there …

4

Eeee? So what do I do? Just thrash it and send you request about new key? :slight_smile:

Gregor

5

read other post. it will not die

6

there are cf socket in rb500 right??

7 
  write-sect-since-reboot: 129728
         write-sect-total: 3556164

This is an older Sandisk…still chiggin’ away. Note that if you use NTP, writes will increase much faster.

8

True? Server or client?

Mike

9 
  write-sect-since-reboot: 3915872
         write-sect-total: 4417528

PQI flash.

Supposedly you get about 300,000 writes per sector and the flash itself manages the wear leveling, so I don’t know if its worth worrying about anymore.

Sam

10

In my experiences, it’s been with the NTP Client. I actually don’t use the client anymore because of this (and my paranoia about the flash failing) although it is still running on this particular router. The uptime of that router I posted stats on is only ~4 days, and there’s been 129,000 writes to it already - the ntp client is running on this. DHCP server “store leases to disk” is set to never. There’s really not much else running on this that would cause this many writes. It’s a hotspot gateway. There is no logging to disk either.

In contrast, here’s another with basically the same config (this network is actually busier), but NTP client is not running:

                   uptime: 2d1h10m34s
                  version: "2.9.24"
  write-sect-since-reboot: 988
         write-sect-total: 617168

Only 1000 writes total in 2 days vs. 129,000 over 4 days on the other one.


As for the PQI flash cards…good cards, but man these killed us awhile back as they don’t work on a Soekris4801 :imp:

11

I use ntp client and I have big number of writes. Mikrotik? Can you do something with ntp client?

12

Thanks, jarosoup.

We have several RB112s for testing in the field that came with bad blocks. We reformated and they are gone but are concerned about the future since the nand is embedded. I’ll try without the NTP client. Not sure why NTP would write to disk…

Mike

13

Glad to pass this along.

It really makes no sense to me either. It’s the only thing I’ve changed on these routers that has shown this sector write difference. We just put up with june 2000 or 1980 and use the uptime to calculate the date :blush: :smiling_imp:

Edit: FWIW, 2.8 has this same behavior with ntp.

14

Have never had a problem with any of my flash modules

                   uptime: 3w2d3h13m3s
                  version: "2.9.24"
  write-sect-since-reboot: 2978210
         write-sect-total: 13400762

That one had been around since 2.7.x

15

That one had been around since 2.7.x

Wow, that’s impressive :open_mouth: This is good news for a lot of people I think. What brand (or chip) of flash card is this?

16

That one I can’t remember exactly, it’s one of the direct IDE plugins into a standard motherboard, acting as my primary router with 9 network interfaces. All of which are graphed. Been thinking about putting a second disk on chip module for storing graphs and logs. Haven’t checked into it fully, but I could have sworn that I heard it was possible. As you can see I get some use out of my equipment. :smiley: And so far (Knock on wood) not a single problem. For all my compact flash modules I have been sticking with SanDisk, for testing I have been using Verbatim (got them cheap). A little off topic, but for my web proxy drives I only use Seagate drives. Everything always well tested even before thinking about loading anything on them.

17

wow, very nice examples, people. thanks!

18

I have not a compact flash drive, and my mikrotik is installed on… 80GB Seagate drive :slight_smile:

19

sometimes those die sooner :slight_smile:

20

like my avatar :slight_smile: This is (or was?) 540MB Seagate…