After the upgrade of my old server to 11.2, I have very slow speed on my HDDs. The system is an old Athlon 800Mz with 5 PATA HDDs (the 5th on an external HDD controller.) acting as a Samba and Print Server.
As you are aware (probably), the 11.2 assigns the /dev/sd? to all drivers. So, my drives are sda, sdb, sdc, sdd
The hdparm is not setting the UDMA and 32bit IO-controls.
According to hdparm, the HDD speeds are (and this is fastest udma2 disk!):
Timing cached reads: 188 MB in 2.01 seconds = 93.72 MB/sec
Timing buffered disk reads: 12 MB in 3.59 seconds = 3.34 MB/sec
The UDMA4, UDMA5 disks have the following speeds:
Timing cached reads: 250 MB in 2.01 seconds = 124.30 MB/sec
Timing buffered disk reads: 66 MB in 3.01 seconds = 21.94 MB/sec
It is an improvement, but it’s not matching the speed I had with 10.3 (> 40MB/s).
The hdparm for the sdd is:
multcount = 0 (off)
IO_support = 0 (default)
readonly = 0 (off)
readahead = 256 (on)
geometry = 4865/255/63, sectors = 78165360, start = 0
According to this, I have 16bit IO_control.
So, how do I set the UDMA on those disks? I have 2 HDDs that are set (I do not know how) to UDMA2. Those disks should be set to UDMA5. hdparm does not set the udma anymore (with DIO_DRIVE_CMD(setxfermode) failed: Invalid exchange)?
It may all be related to the fact that the machine does not meet the requirements for 11.2, but that’s merely a guess. You might need some tuning of the kernel or a module. I have to leave this to the tech gurus.
This is not the case, since it is a headless machine. So, for the job I need it it is more than adequate (think that the usage is less than 8%).
I believe that the problem is somewhere in the modules loaded. I noticed that besides via_pata and via_sata that are loaded, the ide_generic is loaded too. I believe that I do not need it. Follows the lspci. If that is the case, how do I ‘blacklist’ the ide_generic from loading?
00:00.0 Host bridge: VIA Technologies, Inc. VT8363/8365 [KT133/KM133] (rev 02)
00:01.0 PCI bridge: VIA Technologies, Inc. VT8363/8365 [KT133/KM133 AGP]
00:07.0 ISA bridge: VIA Technologies, Inc. VT82C686 [Apollo Super South] (rev 40)
00:07.1 IDE interface: VIA Technologies, Inc. VT82C586A/B/VT82C686/A/B/VT823x/A/C PIPC Bus Master IDE (rev 06)
00:07.2 USB Controller: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller (rev 16)
00:07.3 USB Controller: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller (rev 16)
00:07.4 Bridge: VIA Technologies, Inc. VT82C686 [Apollo Super ACPI] (rev 40)
00:0a.0 USB Controller: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller (rev 62)
00:0a.1 USB Controller: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller (rev 62)
00:0a.2 USB Controller: VIA Technologies, Inc. USB 2.0 (rev 65)
00:0a.3 RAID bus controller: VIA Technologies, Inc. VT6421 IDE RAID Controller (rev 50)
There have been problems with the VIA chipsets, especially in older machines. Try using “pci=nomsi” as a kernel boot argument. If that doesn’t work, search the forums on “nomsi” and you will find other kernel argument which involve dealing with clock issues; there are at least a half dozen to try (which offhand I don’t remember, you’ll find them with a search).
I doubt the problem is with ide_generic. As root do “lsmod | grep ide” and look for that module in the right-side column; it will be a dependency for the module named on the left-side.
I have not search yet, but it seems that the removal of ide-generic and ata_generic, boosted the ide. Of course the performance of all drives is not very good (25-30Mb/sec, and I do remember something link 35-45Mb/sec on the 10.3 installation). So, the problem is partially solved.
In case someone is interested:
Go to System/sysconfig editor
Under System/kernel edit the initrd_modules and remove the ide_generic, ata_generic
Note: before doing so, use the lsmod | grep -i ata and lsmod | grep -i ide. Be sure that the ide_generic and ata_generic is not used by another subsystem.