Yeechang Lee wrote:

Steve Cousins wrote:


Make sure you match the file system chunk size to the RAID stripe
size too.



I don't think this is an issue with JFS; that is, mkfs.jfs doesn't
offer any such options in the first place.



OK. I've never used JFS. XFS has worked really well for us. One nice
thing when testing different configurations is that the file system
creates very quickly. mkfs.xfs also can figure out the chunk size
automatically if you use Linux software RAID. If you do go with RAID6
and a hot spare though make sure you use a very new version of the xfs
tools because I found a bug with it not using the correct chunk size.
The hot spare was throwing it off. They fixed it for me and I believe
it is in the latest version.

Another thing that I ran into is that if you ever want to do a xfs_check
on a volume this big it takes a lot of memory and/or swap space. On a 5
TB RAID array it was always crashing. I have 3 GB of RAM on that
machine and it wasn't enough. I ended up adding a 20 GB swap file to
the 3 GB swap partition and that allowed xfs_check to work. I don't
know if JFS has the same memory needs but it is worth checking out
before you need to run it for real.

Good luck and Happy Holidays,

Steve