NETGEAR is aware of a growing number of phone and online scams. To learn how to stay safe click here.
Forum Discussion
Ready NAS104 - Bit rot protection - silent error
I purchased and setup a ReadyNAS 104 10 days ago and set it up with 4x4TB WD Red drives. Its running firmware 6.2.2.
I then copied around 3.5TB of data (mainly media files) from old USB drives to the NAS and everything has been fine until yesterday when I got a slew of warnings (around 80 email alerts) all saying
warning:volume:LOGMSG_BITROT_WARN Bit rot protection has detected a silent error within /path/to/some/media/file on /dev/sda3 and cannot correct the error.
The errors were in two files. I have since replaced these files with equivalents from a different source and run a disk test which reported no errors although I am not sure where to look for results - there were no more warnings and nothing added to the web visible logs other than disk test started, disk test completed. The test took 11 hours approx.
I have downloaded a set of logs after the disk test but am not sure what to look for. The volume.log file says (for all four drives)
Reallocated Sectors: 0
Reallocation Events: 0
Spin Retry Count: 0
Current Pending Sector Count: 0
Uncorrectable Sector Count: 0
but the smart_history.log file has not been updated past the initial first time startup logs on Feb 20th.
Should I be concerned about this? Thanks for any advice.
I then copied around 3.5TB of data (mainly media files) from old USB drives to the NAS and everything has been fine until yesterday when I got a slew of warnings (around 80 email alerts) all saying
warning:volume:LOGMSG_BITROT_WARN Bit rot protection has detected a silent error within /path/to/some/media/file on /dev/sda3 and cannot correct the error.
The errors were in two files. I have since replaced these files with equivalents from a different source and run a disk test which reported no errors although I am not sure where to look for results - there were no more warnings and nothing added to the web visible logs other than disk test started, disk test completed. The test took 11 hours approx.
I have downloaded a set of logs after the disk test but am not sure what to look for. The volume.log file says (for all four drives)
Reallocated Sectors: 0
Reallocation Events: 0
Spin Retry Count: 0
Current Pending Sector Count: 0
Uncorrectable Sector Count: 0
but the smart_history.log file has not been updated past the initial first time startup logs on Feb 20th.
Should I be concerned about this? Thanks for any advice.
12 Replies
Replies have been turned off for this discussion
- I wouldn't be overly concerned about this.
If smart_history.log has not been updated then that means there hasn't been SMART errors. - Thanks for the very quick reply.
Is it likely that these bit rot protection warnings are false positives? Any information or ideas on why they would be generated?
Is it possible that the file was "already corrupt" (whatever that may mean) before I copied to the NAS? jonrico wrote:
Is it likely that these bit rot protection warnings are false positives? Any information or ideas on why they would be generated?
They may be. Did you download the logs shortly after you started getting these errors?jonrico wrote:
Is it possible that the file was "already corrupt" (whatever that may mean) before I copied to the NAS?
In that case the checksum would have been of an already corrupt file. It is possible that the file could be corrupt before being copied to the NAS but that has nothing to do with this error.
If you compared a checksum of a copy of the file you have elsewhere and a checksum of the file on the NAS before you overwrote it you could have seen if the files matched.- Thanks again. I did download a set of logs shortly after getting the errors, but I am not sure if I still have them. I can check when I get home tonight. If I did have them would they be worth sending to you?
I am afraid that I don't have a copy of the files as they were on the NAS. Almost as soon as I overwrote the files I realised that was probably a bad idea! - I have mailed you the logs I got when I first got to the NAS after the warnings. That was 6 hours after the actual events started.
Thanks again for any information. - Were you reading the files when you got the errors? Or did you receive the errors while you were initially copying the data to the NAS?
- No, I received no errors on first copying data to the drives.
I was not using the NAS when it reported the bit rot warnings. I had setup the email alerts and noticed that I had (80) emails a few hours after the events and that is when I downloaded the logs. A plex server indexes those files but nothing had changed on the plex server's watched filesystems, but it is possible that it was accessing the folder for some reason.
There have been no errors or warnings since. - Last night I got another 14 alerts from another file in the same folder.
This time I made a copy of the file and have checked it against the original file I copied onto the NAS (I still have the original source media). They have the same SHA256 so it seems that this file is unchanged since I first copied it.
I also have a set of logs from 10 minutes after the alerts were sent. Quickly checking those indicates no smart errors and nothing in volume.log that looks odd.
Should I mail these logs as well? This is giving me some concern and I would like to know what is happening here. - Do you recall when you put this data on your system? Was it before or after the firmware upgrade to 6.2.2?
- The system is brand new. I put the 4 drives in it, switched it on and it upgraded to 6.2.2.
It then started to rebuild the raid array (and I left it to do that for the 40 or so hours it took) and when that was finished I copied all the data - so after the 6.2.2 upgrade.
The NAS ran without warnings for around 9 days then the first set of warnings came, another day or two then the second set of warnings.
NETGEAR Academy
Boost your skills with the Netgear Academy - Get trained, certified and stay ahead with the latest Netgear technology!
Join Us!
