start at make you hardware faster with your linux after make your device faster with your filesystem (xfs, reiserfs, ext4???) after make you application faster with your filesystem (for mysql: myisam with fixed table type is faster than dynamic table type and faster than aria(mariadb) page table type) 2011/1/18 Roberto Spadim <roberto@xxxxxxxxxxxxx>: > performace increase= > good algorithm for minimal read/write time > +high speed disks (latency and read / write > time/unit(bit,byte,page), latency = time to head position at the right > sector, cilinder, etc etc, read/write speed = time to read/write a > block of bits/bytes/pages) > + fast filesystem (without many writes like journaling... but > it´s not crash safe....) > + faster memory caches (for read we could cache information that > don´t change... if it change on next read it will be cached) > > see that: > filesystem is a upper level (not device level) > cache is a under level (operational system level, maybe raid cache, > maybe filesystem cache, maybe another cache) > high speed disk (a physical level) > algorithm (the raid level) > > we could implement raid at filesystem (ok it´s not mdadm)... (brtfs if > i´m not wrong, and fuse raid system (a userspace raid software using > diferent filesystems)) > since we want speed, get it closer to hardware (device) like md linux do > better than it just a dedicated hardware (faster than your cpu+memory+linux) > > the problems are: more secure (file system/checksums/jornaling) = more > writes, more writes = more i/o, more i/o = more reads/writes = less > usefull information (file). > got? > > > > 2011/1/18 Igor Podlesny <for.poige+linux@xxxxxxxxx>: >> I had experience of using FreeBSD's vinum (another software RAID). >> Its author, Greg Lehey, stated in vinum's manual: "... A good >> guideline for stripe size is between 256 kB and 512 kB. Avoid powers >> of 2, however: they tend to cause all superblocks to be placed on the >> first subdisk. ..." >> >> Meanwhile, with LSR we're given exactly 2^n choices, for e. g., >> neither 768 KiB, nor 387 KiB won't go: "mdadm: invalid chunk/rounding >> value: 387". >> >> So, why... ($Subj) and how complex would it be to abolish this >> restriction? I think this could be a key to performance increase. >> >> P. S. Thanks a ton for LSR, Neil, BTW. :-) >> >> -- >> End of message. Next message? >> -- >> 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 >> > > > > -- > Roberto Spadim > Spadim Technology / SPAEmpresarial > -- Roberto Spadim Spadim Technology / SPAEmpresarial -- 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
