File Fragmentation

[queeg]

Does file fragmentation have much of an effect on unRAID performance?

[purko]

Does file fragmentation have much of an effect on unRAID performance?

 

No.  Reiserfs is really good at keeping fragmentation low.  That's never really an issue on unRAID.

 

[Guest smnas]

Yeah the Reiserfs is a robust File System and doesn't need to be defragged by any utility as it self-manages itself quite well while its writing data to the volume. Reiserfs has a feature called Tail Packing, embedded into it to reduce internal fragmentation. This works by packing certain files closer together in the same area of the drive, thus reducing read/write time in the long run. The Reiserfs has its advantages and disadvantages too, but it is a tried and true FS.

I'd suggest to do a Parity Check at least once a month to ensure data integrity is up to scratch and that both the parity drive or other data drives have no errors. If you get one or two errors, it should be fine, but if you get heaps of errors, a dodgy drive might need to replaced. Cheers!

[Joe L.]

I'd suggest to do a Parity Check at least once a month to ensure data integrity is up to scratch and that both the parity drive or other data drives have no errors.

excellent advice.

If you get one or two errors, it should be fine

Really BAD advice.

 

If you get ANY parity errors, and you did not power down unexpectadly since your last parity check, it is a sign of a problem. 

 

In other words, if you cleanly stopped the array prior to any power down, you should NEVER see a parity error, ever, unless you have a hardware issue that is unresolved.

[Guest smnas]

That is correct come to think about it. I should of mentioned that if the unRAID did do a graceful shut down to unmount the file systems, and if you get an error, alarm bells should be ringing. Excellent correction Joe L, Cheers!