On Mon, 2007-06-25 at 11:49 +0200, Carlos E. R. wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > > The Sunday 2007-06-24 at 23:06 -0400, James Knott wrote: > > > > netfinity:~ # mdadm --add /dev/md0 /dev/sdd2 > > mdadm: add new device failed for /dev/sdd2 as 4: Invalid argument > > > > If I now reboot, I'll be able to add the drive, using the same command, > > like so. > > I would say that the kernel does not support hot swapping of disks. In > fact, I read time ago it didn't and was work in progress. I don't know > what is the current state.
The kernel does indeed support hot swapping. However, the quality of this depends on the underlying hardware. For example, the intel ICHx chips require that there be a disk in the machine when it is powered on. After that you can hotswap. Don't forget the hotplug option in /etc/fstab (or wherever you put the mount options). Also, the ICHx chipset seems to require time to sense that a swap has indeed happened. So I always: 1. umount the disks to be removed. 2. remove the disks 3. wait, say, 30 seconds. During this time you should see messages in /car/log/messages that the disks have been removed. If you are using intel ICHx chips, you may even see messages about disks being removed and waiting for the hardware to calm down. 4. insert the new disks. I do this in a system with 4 swappable SATA disks. I think it requires a kernel newer that 2.6.17. Otherwise you need to update the libata in your kernel to a newer version. Hotswapping (intel ICHx at least) did not really work in kernels older than 2.6.17. I do no know about hot swapping on other hardware. My understanding is that in most hardware it works ok. Only the intel ICHx stuff is problematic to some odd hardware quirks. One more thing: I have a udev rule so my SATA disks have the same kernel name when they are put in the same physical slot (I have 4 removable SATS disks bays). If you do not have this, sdd can become sde (and so on) after a swap. /var/log/messages tells what the inserted disk is known as. Perhaps it is as simple as that. > > - -- > Cheers, > Carlos E. R. > > -----BEGIN PGP SIGNATURE----- > Version: GnuPG v1.4.5 (GNU/Linux) > Comment: Made with pgp4pine 1.76 > > iD8DBQFGf4/ntTMYHG2NR9URAsXRAJ0ft2C+Rjsr5XrOc9yyx9E5Z7HiNACbBMKv > AufTjctO9G3gujccqtriZHk= > =8fcA > -----END PGP SIGNATURE----- > -- Roger Oberholtzer OPQ Systems / Ramböll RST Ramböll Sverige AB Kapellgränd 7 P.O. Box 4205 SE-102 65 Stockholm, Sweden Tel: Int +46 8-615 60 20 Fax: Int +46 8-31 42 23 -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
