On 2014-09-24 0:09, Stan Hoeppner wrote: > If you create any striped arrays, especially parity arrays, with md make > sure to manually specify chunk size and match it to your workload. The > current default is 512KB. This is too large for a great many workloads, > specifically those that are metadata heavy or manipulate many small > files. 512KB wastes space and with parity arrays causes RMW, hammering > throughput and increasing latency. Thanks again for the valueable information. I used to work with databases on storage subsystems, so placing GBs of database containers for tableapaces on arrays with a larger stripe size was actually beneficial. For log files and other data I usually used different cache settings and strip sizes. So how does this work with SW RAID? Does the XFS chunk size equal the amount of data touched by a single r/w operation? I'm asking because data is usually written in page/extent sizes for databases. Even if I have a container with 50GB, I might only have to read/write a 4k page. Cheers, K. C. -- regards Helmut K. C. Tessarek lookup http://sks.pkqs.net for KeyID 0xC11F128D /* Thou shalt not follow the NULL pointer for chaos and madness await thee at its end. */ _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
