On Thursday 11 August 2011 12:52:36 Bachsau WebWorX wrote:
Now, you have to make your partitions to start at megabyte boundaries to
get full speed, so that the sectors oft the file system come to lie on
the physical sectors, or else it will need read out every sector before
writing to it.
Thanks for everyone's help. I found something about these "Green" drives going to park every 8 secs so I used
hdparm -S 242 /dev/sdd
to change the standby. That brought a tiny improvement. So the next step I deleted the whole lvm and used some other advice by running
cfdisk -h 224 -s 56 /dev/sdd
Which gives a partition table that isn't at all divisible by 8 or start on 2048 but performance had improved quite dramatically. Originally I got 71MB/s when writing one large 20GB file. Writing to a raw partition I now get 117MB/s (also with lvm). Is that what I should be achieving?
I just wonder whether I've got it right now as the partition table looks plain weird..
fdisk -lu /dev/sdd
Disk /dev/sdd: 2000.4 GB, 2000398934016 bytes
224 heads, 56 sectors/track, 311465 cylinders, total 3907029168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk identifier: 0x0005f6d7
Device Boot Start End Blocks Id System
/dev/sdd1 * 56 19531007 9765476 fd Linux raid autodetect
/dev/sdd2 19531008 39062015 9765504 fd Linux raid autodetect
/dev/sdd3 39062016 136717055 48827520 fd Linux raid autodetect
/dev/sdd4 136717056 3907016959 1885149952 fd Linux raid autodetect
mimo