Dear Stefan, In message <4C0AC6E4.4080408@xxxxxxxxxxxxxxxxxx> you wrote: > > I guess you couldn't find much about this as it has more to do with > common sense than magic formulae. If you have 4k-sector drives, align > everything at multiples of 4k, use filesystem-units of multiples of 4k. > As I read and it also seems very logical from the ATA / SCSI point of > view, a stripe size of 256k seems most straight forward. This is the > largest amount of data (a.t.m.) that can be read or written with a > single command to a disk. And why would that be optimal, in general? For example, in a file system I have here (with some 15 millions files) we see the following distribution of file sizes: 65% are smaller than 4 kB 80% are smaller than 8 kB 90% are smaller than 16 kB 96% are smaller than 32 kB 98.4% are smaller than 64 kB With many write accesses going on, a stripe size of 16 KiB gives much better performance. I think you cannot recommend a stripe size or other specific tuning measures without exactly knowing the characteristics of the load. Best regards, Wolfgang Denk -- DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd@xxxxxxx Accident: A condition in which presence of mind is good, but absence of body is better. -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
