RE: clock drift with two Promise Ultra133 TX2 (PDC 20269) cards
From: Drew Winstel <hidden>
Date: 2005-05-03 14:22:18
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Hello,
I'm running 2.6.11.8 on an server with two Promise Ultra133 TX2 (PDC20269) PCI cards, same hardware revision (judging from stickers on the cards). I'm using the CONFIG_BLK_DEV_PDC202XX_NEW driver. Each card has two connected hard drives. Whenever I read from a disk on one of the cards (e.g. using 'dd if=/dev/hdX of=/dev/null bs=1M'), and at the same time read from a disk on the other card, there is heavy software clock drift. It drifts about 2-5 seconds per minute.
This does not happen if I read from two drives connected on the same card, or if I read from a drive connected to the motherboard IDE (VIA vt8233a) and a drive on either of the Promise cards.
Oskar Liljeblad (oskar@osk.mine.nu)
Just to verify your setup: You have a total of four hard drives connected to your PDC20269, hde, hdg, hdi, and hdk, correct? Are all four drives running in DMA mode? Please post the output of lspci -vv and hdparm run on each of the four hard drives. Also, you may want to try downloading and using Albert Lee's pata_pdc2027x driver (part of libata-dev-2.6 tree). See info at my thread from earlier: http://marc.theaimsgroup.com/?l=linux-ide&m=110902518625384&w=2 Download the latest libata-dev patch set at http://www.kernel.org/pub/linux/kernel/people/jgarzik/libata/ Hope this gets you started. Drew