Hi all,

I recently tried to plug a removable SATA drive caddy into my Fedora 8 system and found that when I removed the drive, the device point (/dev/sdb) disappeared, but didn't re-appear when I plugged in a new drive.

I think that particular onboard SATA chip doesn't support hot plug from memory (not at the PC to give specs, but will update on Monday when I am). Again from memory, it was using the PIIX driver.

Soo.... I searched for a chipset that did support hot plug / hot swap and found that the Silicon Image 3112 / 3114 chipset should (IIRC). So, I went and bought an SI3112 PCI card and booted up with two removable drives plugged in. Both detected (/dev/sdb and /dev/sdc) but removing one drive and plugging in a new one, it's no longer detected.

Does anyone know how I get hot plug / hot swap for a SATA chip to be supported? Kernel parameter? modprobe.conf option?

I even tried on my MSI K9N SLI Platinum (NVidia 570 SATA controller), but it doesn't recognise new devices once the system is running. Rebooting and the drives are there, but not while it's running.

A Gigabyte GA-N650SLI-DS4L even comes with an eSATA cable to encourage hot swap of SATA devices, but that didn't work under Linux.

Would gladly try out any pointers to get hot swap of SATA drives working under Linux.

TIA,

LaughingBoy.

Does your system recognize USB devices that are plugged in after Linux is running?

Both my current 780G mboard and a previous Asus with NForce4 do hotswapping of SATA disks. In KDE, just like with the USB thumbdrives, I think I have to right-click and choose to unmount and/or safely remove (just like in windows). Before automounting worked I had to unmount drive before powering down drives. You've probably already tried that.

I think for this to work the sata ports cannot be set to ide-mode in bios.

I have never gotten IDE drives to work with hotswapping and I don't try anymore.

Yes. The automounting daemon does it's job there.

BUT... it doesn't appear to work for SATA drives. I can't even list the new SATA device's partition table (fdisk -l), and nothing is reported in /var/log/messages during subsequent plug in attempts.

I'm trying this on various headless servers, and a workstation with local default (Gnome) login. I hope not to have to run the systems in runlevel 5 to get hot-swap of SATA devices to work!

USB devices don't automount, but can at least be mounted manually if desired. These SATA drives don't even get a mention in /var/log/messages, or show up in a list-partitions-on-all-drives query.

I don't recall seeing that option in any of the BIOSs, but I'll try to have a gander to confirm this.

IDE doesn't support hot-swap in it's spec, IIRC. This was one of the main advantages to go to SATA - incorporating some SCSI technologies into the (P)ATA spec.

Does that agree with your earlier post?

To try the sata hotswap, I inserted a seagate sata 250 gb hd on a removable tray, and powered it up on a running system.

dmesg shows it loading as /dev/sdb with the proper partitions

In x, in system:/media, I right click on each partition of /dev/sdb and unmount (safely remove does not show up as option). Then turn power off of hd tray. Wait a few minutes and turn hd tray power back on. The drive again shows up as /dev/sdb and each partition again shows up and is accessible.

Maybe difference between our systems is hardware. I'm using gigabyte 780g motherboard, forget model but its the microatx 2sh model. I have custom kernel with ide, sata, pata in kernel but with scsi as module. Sata dvd shows up as /dev/sr0.

I don't understand that. If I load HUGE kernel (everything compiled in) sata dvd shows up as /dev/hdc. I'm living with it being sr0 but this difference, or perhaps hardware/bios/kernel, may explain why my non-boot sata drives are hotswappable. In this bios I am able to set sata ports to ide, ahci, or raid. It even lets me set one or two of the ports differently so dvd is supposedly in ide mode (still doesn't work with freebsd though). I'm using 2.6.25.7 kernel but this worked even with whatever came with slackware 12 (2.6.24.17?). I wouldn't swear to it but I think, except for automounting, this sata-hotswapping even worked with the 2.4 kernels which I am using on an nvidia nforce 4 motherboard.

IDE drives... Yes I got a bit off topic.

Good luck.

Nope.

I've tried these kernels:
2.6.23.17-88.fc7
2.6.25.6-27.fc8

One machine (Fedora 8) has these ata-based modules loaded: The other machine (Fedora 7) has these ata-based modules loaded: I was able to find a script to "rescan the scsi bus" and under Fedora 7 (NVidia SATA controller) it worked to find the drive that was plugged in. No such luck under the Fedora 8 system (attached to the Silicon Image SATA card).

Any idea how to turn this ability on?

I don't have any ata in lsmod or any *ata* in /lib/modules so I must have that compiled in kernel. I think the only scsi related module that loaded was sg. This seems odd as I'm pretty sure I compiled kernel with generic scsi driver as module. I'll have to go back and look.

Regardless, my system which is able to hotswap sata hd has ahci running with scsi. Maybe you need this. It loads the pata_atiixp as I have the 780g chipset.

Hope this is of some help