On Wed, Sep 29, 2010 at 12:58 PM, Peter Kjellstrom cap@nsc.liu.se wrote:
On Wednesday 29 September 2010, Boris Epstein wrote:
On Wed, Sep 29, 2010 at 11:53 AM, James A. Peltier jpeltier@sfu.ca wrote:
| However, given the size of the device I assume that this is a raid of | some | sort. You'll want to make sure to run mkfs.xfs with the proper stripe | parameters to get the alignment right. Also, you may want to make sure | your | LVM or partition table is properly aligned.
...
I am wondering if I need to worry about stripe and width though as mine resides on a logical volume residing on a hardware-controlled RAID 6 device (i.e., one slice as far as the OS is concerned).
That is why you need to consider it. If the device is aligned on stripe size (chunk size * (number of drives - 2 for raid6 parity)) and the filesystem is made aware it can put stuff (files, metadata, etc.) so that a minimum of stripes are touched (less I/O done).
/Peter
Boris.
CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Well, you are interfering with the hardware RAID controller which copies around and stripes data as it sees fit. I am not sure with this many levels of abstraction I can gain any measurable performance improvement by adjusting the XFS to the controller's hypothetical behaviour.
Boris.