On Tuesday 21 August 2007, Feizhou wrote:> Les Mikesell wrote:
> > Jim Perrin wrote:
> >>> Should it be possible to hot-swap SATA drives with Centos5?
> >> Depends on the SATA controller, but yes. If the controller allows,
you
> >> can hotswap sata drives.
> > How are the names supposed to work when one may be missing at bootup
and
> > added later?
> I thought the system would just assign the next available /dev/sdx?
> Then there was the post about wanting to be able to pull a SATA/eSATA
> disk in and have the system automatically mount whatever filesystem is
> on the disk...
That was mine. Still working on it.
As to the hardware support, the definitive answer is found at
www.linux-ata.org
As to device naming, use LABEL= to fix that. SCSI device naming on Linux
stinks.
I'm dinking around with a Ubuntu install right now that is giving me fits
because of linux PCI/SCSI weirdness. The boot drive (as set in the BIOS) is
probed by the kernel as /dev/sdc. Fun. The setup has two 80GB drives in MD
RAID1 (200MB /boot on /dev/md0, and 77GB / on /dev/md1, both on the same
drives) and four 250GB drives in 3-disk RAID5 with a hotspare. The drives
are spread on three two port controllers (no, I don't have a four or six
port
controller handy, not an option in this case). Still working grub to get the
thing to boot....
LABEL= does actually have its uses; I migrated a filesystem on a CentOS 4 VM
running on one of our two VMware ESX beasts (2x Dell 6950, 4x dual core
Opterons, 32GB RAM each, dual 4Gb/s fibre-channel to 2x EMC CLARiiON
CX3-10c's with 20TB each) from the internal 3x300GB RAID to a 1.95TB LUN on
the CX3. By using LABEL=, I was able to blow the drive away in VI Client on
the VM, and boot right up without device ordering problems.
But I have also been bitten by the 'LABELs are the same on cloned disks'
fun
and games....
What I'm currently doing with the eSATA deal is having an entry in fstab,
set
to noauto, and using LABEL=, and an icon in KDE to mount it on the desktop.
it is not seamless; unmounting is much more of a chore, as KDE has fun with
the icon, doesn't enable the context menu 'safely remove' (aka,
unmount)
option, etc. But it's better than nothing. Just haven't had time to
see how
to enable SCSI removable support (dig through the udev and hotplug stuff
sometime and you'll see what I mean) in libata as yet. With SCSI removable
support (which usbstorage implements, which is why it works) the system Just
Works properly.
--
Lamar Owen
Chief Information Officer
Pisgah Astronomical Research Institute
1 PARI Drive
Rosman, NC 28772
(828)862-5554
www.pari.edu