Todd and Margo Chester wrote:
Robert Hancock wrote:
Todd and Margo Chester wrote:
Robert Hancock wrote:
Todd and Margo Chester wrote:
Hi Jeff,
I am having a nasty problem with hot swapping a removable (not
eSATA) drive I use for backup on several servers. It is reported
over on
http://bugs.centos.org/view.php?id=3391
Trying to help me find a work around to the problem at
http://www.centos.org/modules/newbb/viewtopic.php?topic_id=18608&start=0#forumpost68783
Alan posted your ata_piix.c code at
http://centos.toracat.org/ajb/tmp/toddandmargo/ata_piix.c
He pointed out
1483 /* no hotplugging support (FIXME) */
1484 if (!in_module_init)
1485 return -ENODEV;
What do you mean by the comment in line 1483? Is there some
know issue with hot swapping SATA drives?
If you're using the ata_piix driver then it means your motherboard
is not in AHCI mode, so hotplugging is not supported by either the
driver or controller. You have to enable AHCI for SATA hotplug to
work on Intel controllers.
Hi Robers,
As far as I can tell, ACHI is turned on on my motherboard.
I have tried all variation in bios (one of them turns /dev/sdb
into /dev/hda). Does not mean ACHI is working right.
Do you know of any reason why my kernel
(CentOS 5.2: 2.6.18-92.1.22.el5) would not support
(bugs, etc.) hotplugging?
Also, do you know of a utility that I can use to
ask ACHI what is has for me (give me a report)?
Many thanks,
-T
If the device is in AHCI mode then the ata_piix driver won't load for
it - at least it won't in current kernels, I can't say for sure that
it won't in the CentOS 5 version.. You do need to get it using the
ahci driver instead of ata_piix or hotplug definitely won't work.
You can try changing the boot initrd to try to load the AHCI driver
instead by changing the scsi_hostadapter entry in /etc/modprobe.conf
to be ahci instead of ata_piix, then rebuilding the initrd or
reinstalling the kernel RPM. However, if the BIOS isn't set up
properly for AHCI mode to work, you'll have to either boot up in
rescue mode and fix it, or boot up from a different kernel entry in grub.
Hi Robert,
Thank you. I take it there is no probe of the AHCI module. Rats!
My /etc/modprobe.conf (BIOS: Enhanced SATA Mode):
alias scsi_hostadapter sata_sil
alias eth1 e1000e
alias scsi_hostadapter1 megaraid_mbox
alias scsi_hostadapter2 ata_piix
alias snd-card-0 snd-intel8x0
options snd-card-0 index=0
options snd-intel8x0 index=0
remove snd-intel8x0 { /usr/sbin/alsactl store 0 >/dev/null 2>&1 || : ;
}; /sbin/modprobe -r --ignore-remove snd-intel8x0
In CentOS 5 this file mainly gets set up by the installer. If you change
your BIOS settings you'd have to change it manually and rebuild the
initrd for the changes to take effect.
While fooling around with my BIOS, trying to see what happens
in the various SATA modes, the one called "ACHI Compatibility mode"
changed my removable drive from /dev/sdb to /dev/hda. ("mount /dev/hda"
still hangs for two minutes, then the kernel freezes.)
Yeah, compatbility mode likely isn't what you want. It likely sets up
the controller for IDE mode.
Motherboard makers are sometimes pretty bad about labelling the settings
properly. Often AHCI is labelled as RAID mode or something.
I am wondering if there is a clue here. Does the ACHI module load
drives as /dev/sd* or /dev/hd*?
It will be sd*
Many thanks,
-T
p.s., just of curiosity, what would the ACHI module look
like in my modprobe.conf?
You would change:
alias scsi_hostadapter2 ata_piix
to
alias scsi_hostadapter2 ahci
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