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Title: Very slow disk IO on SATA RAID1 Jetway NC92-330-LF Post by: DFen on Friday 25 June 2010, 02:53:39 am I have installed endian on a Jetway NC92-330-LF MB with two SATA HDD in software RAID1
Apart from the install being very slow, after installation I am seeing extremely slow IO on the hard disks. hdparm -tT /dev/hda /dev/hda: Timing cached reads: 2392 MB in 2.00 seconds = 1195.39 MB/sec Timing buffered disk reads: 10 MB in 3.08 seconds = 3.25 MB/sec I was also surprised to see the disks using device hdX and not sdX! Am I missing something here or does endian CE not fully support SATA? Title: Re: Very slow disk IO on SATA RAID1 Jetway NC92-330-LF Post by: DFen on Saturday 26 June 2010, 12:17:47 am Just a follow up on my problems with 2.4 IO speed
I installed 2.3 on the same machine with no speed poblems at all hdparm was showing 100MB/s Buffered read speed. I also note that 2.3 was using kernel module libata and ata_piix as well as some scsi modules. libata is NOT present on my copy of endian CF 2.4 Can anybody suggest where I can get additional kernel modules? Further follow-up ============ I have upgraded using efw-upgrade and the system has reverted to being very slow!! The disk devices are now showing as hda and hdb instead of sda and sdb (I guess having raid 1 md devices allows it to boot) kernel mosule ata_piix is loaded but no sign of libata. This looks to me similar to the problem found at: h**p://bugs.endian.com/view.php?id=208 Yet more follow up 3/July/2010: I am not at all sure where the problem lies however it appears that libata is built in to the kernel and not created as a module. I have tried ordinary IDE disks and the speed problem remains the same. I suspect now that this problem relates to the removal of Combined mode in kernel 2.6.22 I understand this may cause problems when the OLD ide drivers are included in the kernel along with libata drivers. I will be the first to admit I don't understand all this, but see the following references: Combined mode h**p://www.mail-archive.com/linux-ide@vger.kernel.org/msg04681.html Performance issues after combined mode removed: h**p://forum.soft32.com/linux/Combined-mode-quirk-removal-kills-performance-ftopict345203.html Related stuff I don't understand h**p://forum.soft32.com/linux/PATCH-22-remove-Intel-combined-mode-quirk-ftopict341159.html A possible fix in kernel config h**p://linux.derkeiler.com/Mailing-Lists/Kernel/2007-07/msg08563.html Now all I need is to try a kernel built to endian standards but without the old ide driver!! |