also sprach martin f krafft <madduck@debian.org> [2003.08.21.1254 +0200]: > > Do all disks have DMA turned on? > > This might be the problem. I turn DMA on, always, in /etc/inittab. > But it doesn't work. Check this: > > ailab:~# hdparm -d1 /dev/hda > > /dev/hda: > setting using_dma to 1 (on) > HDIO_SET_DMA failed: Operation not permitted > using_dma = 0 (off) This was the problem, I had compiled the kernel for the wrong chipset. Now it's fixed, now I have DMA, and now I get about 170% of the read performance of the previously fast system. Write performance dropped to about 99.7%. Cool. I would still appreciate comments to the following: > > Try with the defaults values for chunk size, algorithm and ext3 stride. > > Which are? I could not see any. > > > Use an external journal for ext3 that is located on a RAID1. > > Does this really increase performance if the RAID1 would be on the > same disk(s)? I note that RAID1 give absolutely no speed improvement > on writes. RAID5 does a little. And journals are more written than > read, no? -- Please do not CC me when replying to lists; I read them! .''`. martin f. krafft <madduck@debian.org> : :' : proud Debian developer, admin, and user `. `'` `- Debian - when you have better things to do than fixing a system Invalid/expired PGP subkeys? Use subkeys.pgp.net as keyserver!
Attachment:
pgp0L0GL8VQ2G.pgp
Description: PGP signature