Im a little leary on what they (errors)mean.  If say, for example, i have a server with 5 hard drives in it.  1 parity and 4 data. If i get, i dont know, 10 errors on drive #3, what does that mean?  everything will still play right?  the parity has no errors so why wouldnt the parity just fix those errors?  am i understanding this right?

 

thanks

Im a little leary on what they (errors)mean.  If say, for example, i have a server with 5 hard drives in it.  1 parity and 4 data. If i get, i dont know, 10 errors on drive #3, what does that mean?   everything will still play right?  the parity has no errors so why wouldnt the parity just fix those errors?  am i understanding this right?

 

thanks

 

Below is an excerpt from the Troubleshooting page that explains what causes errors and what unRAID does with them.  But if you got 10 errors on the same disk all at once that is sounding more like a calbing problem or a rapidly failing disk than a simple bad sector developing.  Why don't you run a syslog and a smartctl report on the drive and post it.  (Directions are also on the Troubleshooting page, which is linked in my sig).

 

What if I get an error?

 

- If your array has been running fine for days/weeks/months/years and suddenly you notice a non-zero value in the error column of the web interface, what does that mean? Should I be worried?

 

- Occasionally unRAID will encounter a READ error (not a WRITE error) on a disk. When this happens, unRAID will read the corresponding sector contents of all the other disks + parity to compute the data it was unable to read from the source. It will then WRITE that data back to the source drive. Without going into the technical details, this allows the source drive to fix the bad sector so next time, a read of that sector will be fine. Although this will be reported as an "error", the error has actually been corrected already. This is one of the best and least understood features of unRAID!

 

- There may be OTHER types of errors than this one, so it is certainly worth your while to capture a syslog after an error is detected, but this is likely what has happened. Also, if you notice this happening more than once in a very great while, you might want to consider testing and replacing the disk in question. Remapped sectors have been linked with higher than normal drive failure.

 

- After getting an error, run a parity check soon after, to make sure that all is well.

 

Thanks!  my parity drive stopped being read but i fixed it(im still not sure what the hell i did to fix it) and added a new 1.5tb drive to replace a 500 gig to get some more space. when i rebooted i noticed 7 errors on one of my newer disks.  It is rebuilding the drive i replaced (and taking its good old time might i add) so when it is done rebuilding i will run a parity check and see how goes it.  Then i will run a syslog.

 

thanks again.  I appreciate it. 

Thanks!  my parity drive stopped being read but i fixed it(im still not sure what the hell i did to fix it) and added a new 1.5tb drive to replace a 500 gig to get some more space. when i rebooted i noticed 7 errors on one of my newer disks.  It is rebuilding the drive i replaced (and taking its good old time might i add) so when it is done rebuilding i will run a parity check and see how goes it.  Then i will run a syslog.

 

thanks again.  I appreciate it. 

 

An "error" during a rebuild is much worse than an "error" during normal operation or during a parity check.  During a rebuild, the parity is not valid.  If you get a read error there is no way for unRAID to be able to recompute the failed sector.  The result may well be 7 randomly selected sectors have bad data.  Could be hard to find!

 

Also make sure to post the syslog before you reboot.  On reboot, the syslog is reset and you will lose the history of what has happened.