Harddrives renaming themselves?

[lucky9]

I don't boot with a USB FlashDrive drive plugged in. My two USB HDDs are plugged in all the time....but they aren't turned on when booting.

[BitJam]

@Eadwine, there are two very different things going on here. Your problem has to do with a cdrom drive being treated like a hard drive and thus rendering it inoperable. IMO if this is not due to a hardware problem or a misconfiguration (including a possible misconfiguration in the BIOS) then it is a bug in the kernel.

@everyone,
The other "problem" is less severe. All the device still work, but the names like /dev/sda can be different on different boots. This is exacerbated when you boot from a LiveUSB because that changes the timing of when devices get recognized. This "problem" will not go away. We have been warned about this literally for years. We went through the sometimes painful process of converting our bootloaders and fstabs to use UUIDs instead of device names in preparation for it. We should not be surprised that the this change has finally arrived on our doorstep.

The only way the kernel can reliably provide consistent /dev/sdX names is to delay the boot process until it is sure that all devices of a certain type have been recognized. It was realized years ago that as hardware become more modular and more convoluted, it no longer made sense for people rely on consistent /dev/sdX names. That is why we have the /dev/disk-by/ directories. That is why we identify the root partition by UUID in a boot parameter. That is why we identify partitions in fstab by UUID and not device name.

It's not because people like UUIDs or find them easier or more intuitive to work with. It is because it is no longer practical to keep the /dev/sdX names consistent. Going forward, the solution is actually pretty simple and I've posted it before. We simply stop using /dev/sdX names when identifying devices in the installer. AFAIK, almost all of the information we should use to identify a device is in the output of the command:

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lsblk -o LABEL,MODEL,FSTYPE,RM,MOUNTPOINT,SIZE

See:
Persistent block device naming:

This article describes how to use persistent names for your block devices. This has been made possible by the introduction of udev and has some advantages over bus-based naming. If your machine has more than one SATA, SCSI or IDE disk controller, the order in which their corresponding device nodes are added is arbitrary. This may result in device names like /dev/sda and /dev/sdb switching around on each boot, culminating in an unbootable system, kernel panic, or a block device disappearing. Persistent naming solves these issues.

Persistent storage device names:

In a Linux system (and every other Unix like system), every device known to the kernel gets its own name during the device probing at bootup time. If the probing order does not change across reboots and if the hardware configuration remains the same, those names are stable and there is nothing to worry about.

With new technologies like FireWire, USB and Fibrechannel, devices can be added and removed at runtime. But even in the good old days it was not uncommon to add and remove drives, or to experience hardware failures at runtime. All this leads to a different probing order and the stable kernel device names are in danger for the next boot.

[richb]

That resolves the installer issue, but what about the issue of booting with a USB stick in a port, not from the stick. My internal drives are designated by UUID in fstab but still show sdx designations in a file manager.

I can live with it as I label my drives to avoid confusion. So it is not an issue for me.

[anticapitalista]

richb - the mount points for devices/partitions should also appear as labels or uuid under media in the future. That should also be the case in fstab.

Here is an example of my fstab that we are working on in antiX and MX with Adrian.:

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# Pluggable devices are handled by uDev, they are not in fstab
UUID=3b6c6562-2de0-4f14-993d-8af446a6bf57 / ext4 defaults,noatime 1 1
#LABEL="antiX-64" / ext4 defaults,noatime 1 1
proc /proc proc defaults 0 0
devpts /dev/pts devpts mode=0622 0 0
#UUID=c0c16fbc-1e5a-46a8-9ecd-d064800b1dca swap swap sw, 0 0
LABEL="swap" swap swap sw, 0 0
#UUID=8fa6aecc-c2ee-48c5-9dd8-2e4027187922 /media/sda1 ext4 noauto,users,exec,relatime 0 0
LABEL="antiX-32" /media/antiX-32 ext4 noauto,users,exec,relatime 0 0
#UUID=2c53bf5a-8caa-4534-beb1-f5aa04050918 /media/sda3 ext3 auto,users,exec,relatime 0 0
LABEL="Torrents" /media/Torrents ext3 auto,users,exec,relatime 0 0
#UUID=f56325d7-99bc-4d6d-b84d-b81554a404dd /media/sdb3 ext3 auto,users,exec,relatime 0 0
LABEL="Data" /media/Data ext3 auto,users,exec,relatime 0 0
#UUID=d5b1c53b-8c62-4731-8492-021f22c45b69 /media/sdb5 btrfs auto,users,exec,relatime 0 0 
LABEL="Docs" /media/Docs btrfs auto,users,exec,relatime 0 0
#UUID=8fa6aecc-c2ee-48c5-9dd8-2e4027187922 /media/sdb6 ext4 noauto,users,exec,relatime 0 0
LABEL="MX-14" /media/MX-14 ext4 noauto,users,exec,relatime 0 0

[lucky9]

I'd get more lost if I didn't have everything labeled. I need something I can actually read and know what it is.

[anticapitalista]

I should also have mentioned in my post above the work done/in progress by BitJam in creating an /etc/fstab with labels/uuid which has been incorportaed into the gui installer.

[Eadwine Rose]

I have managed to change the jumper on the Plextor to slave, yay left hand. Sony is still disconnected. Boot order is back to cdrom first. Wait and see what is going to happen from now on!

[Eadwine Rose]

So.. Sony unplugged, Plextor on Slave, nope, not helping either, still happening.

That is all I can do. Going to put this baby's boot order back to harddrive first now. *shrug*