Re: [gentoo-user] Re: mount: special device /dev/hdc does not exist. What does this mean?
On Mon, 21 Jul 2008 02:35:44 +0300, Nikos Chantziaras wrote: Anyway, you don't need to add something to remind you of the partition's position; /etc/mtab will use regular device names, so you can see what's going on with 'cat /etc/mtab' or simply 'mount' without parameters. cfdisk also shows the labels against the partition names. -- Neil Bothwick Don't use a long word if a diminutive one will do. signature.asc Description: PGP signature
Re: [gentoo-user] Re: mount: special device /dev/hdc does not exist. What does this mean?
Hi, Nikos! On Sun, Jul 20, 2008 at 12:29:19AM +0300, Nikos Chantziaras wrote: Alan Mackenzie wrote: The default in new kernels is to only use /dev/sd*. I'm totally confused. Doesn't sd* mean SCSI disk drive? When I was installing Gentoo from the CD, I had to mount my main hard drive as /dev/sdb5. When I built my own kernel, it needed /dev/hdh5. This seems crazy. Is it documented anywhere in Gentoo? Not sure. But if you have /dev/hd* instead of /dev/sd*, it means you configured your kernel with the legacy IDE drivers instead of the new (P)ATA drivers. The new drivers use /dev/sd* (for IDE/PATA/SATA and SCSI alike; there's no difference anymore.) This was indeed the case. The CD/DVD-ROM can show up as /dev/sd* even with the old legacy drivers if you have enable SCSI Emulation for it. In any event, try to build a new kernel using the new drivers. The old legacy driver you're using will probably get declared deprecated at some point (if it didn't happen already). [ Detailed instructions snipped - but they were appreciated and followed :-] Did this. It mapped my two hard drives (previously /dev/hd[gh]) to /dev/sd[ab], and created /dev/sda, dev/sda1, . So far, so good. However, it hadn't created /dev/sda16 or /dev/sda17 for some reason. A quick # ls -l /dev/sd{a15,b} gives: ... 8, 15 /dev/sda15 ... 8, 16 /dev/sdb In a philosophical mood, one might say that the new unified, enhanced, better IDE support is inadequate for my setup. What I actually said, I'm not going to repeat in a public mailing list. So the kernel guys have decided that nobody would ever want more than 15 partitions on a drive. It's a bit like the old MS-DOS restriction to 512 MB all over again. Hey, guys, hard drives nowadays are like 200 gig, not 512meg. What's so wrong about having partitions with sizes 1Gb, 2Gb, 4Gb, with maybe 100Mb for a boot partition? Generic ATA support unless you can't find a native driver for your chipset (I doubt you have some extremely rare/exotic mainboard ;) The HPT370A UDMA100 chip (with my two hard drives) was no problem. For the VIA VT82C586A/B/VT82C686/A/B/VT823x/A/C ordinary IDE chip (the one with my two DVD drives attached), I tried configuring VIA, which didn't work. Then I rebuilt the kernel again with Generic ATA support, which didn't work either. Both of these created /dev/sdc and /dev/sdc1, but no /dev/sdd. When I tried # mount -t iso9660 /dev/sdc /cdrom, I got the something's gone wrong, but we're not telling you what error message. Trying to mount /dev/sdc1 gave exactly the same result. Actually, thinking about it, this was probably my USB stick it was trying to access. Nikos, do you happen to know the appropriate kernel mailing list where I could express the opinion that restricting the number of partitions on a drive to 15 isn't a good tradeoff? All in all, I really amn't impressed with this modern drive support. Besides quartering the max number of partitions on a drive, it confuses IDE and SCSI drives, thus confusing me, too. Previously, when I attached devices to the IDE1 socket, I knew they would appear at /dev/hd[cd]. Now, it would seem, the kernel assigns drives at random to /dev/sd[abcd...], so you can only determine by experiment which devices are at which device. Nothing personal, Nikos. ;-) I think I need to go back to the traditional IDE handling. None of the Gentoo kernels I've built have even seen my two DVD drives, yet. I'll get there, somehow. Thanks! -- Alan Mackenzie (Nuremberg, Germany).
Re: [gentoo-user] Re: mount: special device /dev/hdc does not exist. What does this mean?
On Sunday 20 July 2008, Alan Mackenzie wrote: So the kernel guys have decided that nobody would ever want more than 15 partitions on a drive. From memory I recall that this has always been the limit for SATA/SCSI drives. For ATA drives I think it is 63? Not sure if this is a Linux OS kernel restriction - what is the maximum number that MSWindows see? I would think it is the same. -- Regards, Mick signature.asc Description: This is a digitally signed message part.
Re: [gentoo-user] Re: mount: special device /dev/hdc does not exist. What does this mean?
On Sun, 20 Jul 2008 15:05:10 +, Alan Mackenzie wrote: So the kernel guys have decided that nobody would ever want more than 15 partitions on a drive. It's a bit like the old MS-DOS restriction to 512 MB all over again. Hey, guys, hard drives nowadays are like 200 gig, not 512meg. What's so wrong about having partitions with sizes 1Gb, 2Gb, 4Gb, with maybe 100Mb for a boot partition? Nothing, which is why the kernel includes LVM, allowing you to have many more filesystems on a disk. -- Neil Bothwick c:Press Enter to Exit signature.asc Description: PGP signature
Re: [gentoo-user] Re: mount: special device /dev/hdc does not exist. What does this mean?
Hi, Mick, On Sun, Jul 20, 2008 at 06:22:23PM +0100, Mick wrote: On Sunday 20 July 2008, Alan Mackenzie wrote: So the kernel guys have decided that nobody would ever want more than 15 partitions on a drive. From memory I recall that this has always been the limit for SATA/SCSI drives. For ATA drives I think it is 63? If I do # ls -l /dev/hd[gh], I get: brw-rw 1 root disk 34, 0 2005-02-26 06:43 /dev/hdg brw-rw 1 root disk 34, 64 2005-02-26 06:43 /dev/hdh , which does indeed suggest a max of 63. However, there's nothing on the disk partition structure (which is basically a chain of extended partitions across the entire disk) to limit this. Not sure if this is a Linux OS kernel restriction - what is the maximum number that MSWindows see? What's MSWindows? ;-) Proabably a lot less than 63. However, the limit of 15 (which I didn't know about before) is a good reason for me not to migrate to SATA disks. I _like_ having lots of partitions ~1 - 4 Gb. It was trivial for me to clear a 4 Gb partition for a trial installation of Gentoo (which, by the way, I'm expecting to expand into my prime system - my Debian Sarge is beginning to feel very tired). Shoe horning IDE disks into the S{ATA,CSI}'s 15 partition limit seems an unkind thing to do. Mick -- Alan Mackenzie (Nuremberg, Germany).
Re: [gentoo-user] Re: mount: special device /dev/hdc does not exist. What does this mean?
Nikos Chantziaras wrote: Mick wrote: [...] What would be the recommended way of upgrading from the /dev/hd to /dev/sd then? I have held back doing this because I didn't have the time to mess about with it. If I were to configure a new kernel without legacy ATA drivers, how would I know what my devices will be seen as in advance, so that I can change my /etc/fstab before I reboot? The way I do it, is to label my partitions. If your partitions aren't labeled yet, you can do so with 'tune2fs'. If your /dev/hda1 is your root (/), /dev/hda2 your /home and /dev/hda3 your swap, you can label them with: tune2fs -L GentooRoot /dev/hda1 tune2fs -L GentooHome /dev/hda2 mkswap -L GentooSwap /dev/hda3 Then edit /etc/fstab and change the mount points from: /dev/hda1 ... /dev/hda2 ... /dev/hda3 ... to: /dev/disk/by-label/GentooRoot /dev/disk/by-label/GentooHome /dev/disk/by-label/GentooSwap As reference, here the relevant entries in my own /etc/fstab: /dev/disk/by-label/GentooRoot / ext3noatime 0 1 /dev/disk/by-label/GentooSwap none swapsw 0 0 /dev/disk/by-label/Suckage/windows/C ntfs-3g noatime 0 0 As you can see this even works for NTFS; you use the label you gave the drive in Windows. After you've done these changes, it doesn't matter the least anymore what the actual device name is. You can even move the harddisk to another computer (actually I'm doing exactly that) that totally results in a re-ordering of /dev/sd* entries and it will still mount correctly. Question, if I were to label mine and then boot from a Gentoo or any other bootable CD, would those labels still be there? Dale :-) :-)
Re: [gentoo-user] Re: mount: special device /dev/hdc does not exist. What does this mean?
Nikos Chantziaras wrote: Dale wrote: Nikos Chantziaras wrote: Mick wrote: [...] What would be the recommended way of upgrading from the /dev/hd to /dev/sd then? I have held back doing this because I didn't have the time to mess about with it. If I were to configure a new kernel without legacy ATA drivers, how would I know what my devices will be seen as in advance, so that I can change my /etc/fstab before I reboot? The way I do it, is to label my partitions. If your partitions aren't labeled yet, you can do so with 'tune2fs'. If your /dev/hda1 is your root (/), /dev/hda2 your /home and /dev/hda3 your swap, you can label them with: tune2fs -L GentooRoot /dev/hda1 tune2fs -L GentooHome /dev/hda2 mkswap -L GentooSwap /dev/hda3 [...] Question, if I were to label mine and then boot from a Gentoo or any other bootable CD, would those labels still be there? The labels are part of the file system; they're always there. For example, when booting the 2007.0 LiveDVD (which uses the legacy drivers, meaning /dev/hd* instead of /dev/sd*) the labels are there and I can mount /dev/disk/by-label/GentooRoot just fine. Kwl. Now to see what I can screw up. o_O Dale :-) :-)
Re: [gentoo-user] Re: mount: special device /dev/hdc does not exist. What does this mean?
On Sunday 20 July 2008, Nikos Chantziaras wrote: Dale wrote: Nikos Chantziaras wrote: Mick wrote: [...] What would be the recommended way of upgrading from the /dev/hd to /dev/sd then? I have held back doing this because I didn't have the time to mess about with it. If I were to configure a new kernel without legacy ATA drivers, how would I know what my devices will be seen as in advance, so that I can change my /etc/fstab before I reboot? The way I do it, is to label my partitions. If your partitions aren't labeled yet, you can do so with 'tune2fs'. If your /dev/hda1 is your root (/), /dev/hda2 your /home and /dev/hda3 your swap, you can label them with: tune2fs -L GentooRoot /dev/hda1 tune2fs -L GentooHome /dev/hda2 mkswap -L GentooSwap /dev/hda3 [...] Question, if I were to label mine and then boot from a Gentoo or any other bootable CD, would those labels still be there? The labels are part of the file system; they're always there. For example, when booting the 2007.0 LiveDVD (which uses the legacy drivers, meaning /dev/hd* instead of /dev/sd*) the labels are there and I can mount /dev/disk/by-label/GentooRoot just fine. Yes, labels . . . been thinking of doing this for the last two years! I guess I will have to use reiserfstune for my reiserfs partitions. What about xfs - will xfsprogs do it? Thanks for the tip. The thing with the conventional device numbering system is that you know which one is first, which second, etc. With Labels I'll have to add something to it to remind myself that this is the first partition, etc. Can I have blank spaces in the Label name? -- Regards, Mick signature.asc Description: This is a digitally signed message part.
Re: [gentoo-user] Re: mount: special device /dev/hdc does not exist. What does this mean?
Nikos Chantziaras wrote: Dale wrote: Nikos Chantziaras wrote: Dale wrote: [...] Question, if I were to label mine and then boot from a Gentoo or any other bootable CD, would those labels still be there? The labels are part of the file system; they're always there. For example, when booting the 2007.0 LiveDVD (which uses the legacy drivers, meaning /dev/hd* instead of /dev/sd*) the labels are there and I can mount /dev/disk/by-label/GentooRoot just fine. Kwl. Now to see what I can screw up. o_O I should mention here the old Indian* saying: If it ain't broke, don't fix it. *OK, it's not Indian, but you get the idea. True but I have trouble remembering which partition is home and which is portage, until I mount them anyway. It's obvious then. I guess according to another reply that I will have to use something else for resierfs. I guess it can't hurt to much. Worst thing is to have to boot and edit fstab back to the old way. :/ Dale :-) :-)
Re: [gentoo-user] Re: mount: special device /dev/hdc does not exist. What does this mean?
Dale wrote: True but I have trouble remembering which partition is home and which is portage, until I mount them anyway. It's obvious then. I guess according to another reply that I will have to use something else for resierfs. I guess it can't hurt to much. Worst thing is to have to boot and edit fstab back to the old way. :/ Dale :-) :-) Well bummer, you have to umount it first. O_O That sucks. Somebody tell me it ain't so. Dale :-) :-)
Re: [gentoo-user] Re: mount: special device /dev/hdc does not exist. What does this mean?
Hi, Nikos, On Sat, Jul 19, 2008 at 10:06:15PM +0300, Nikos Chantziaras wrote: Alan Mackenzie wrote: However, I can't access my DVD drives. I know at least one of them works, because I installed Gentoo from it. When I do mount -tiso9660 /dev/hdc /cdrom , it comes back with special device /dev/hdc does not exist. And yes, there was a CD in the drive, and /cdrom exists. What does special device mean here? Does it mean the physcial hardware, the controller chip, the directory entry /dev/hdc, the driver in the kernel, or what? What is special about my DVD writer? /dev/hdc (and other files in /dev) are not called files, they're called special devices). Ah! I really wish they weren't. Didn't they used to be called device files? Well, to answer some of my questions, I was missing a /dev/hdc, so I made one with # mknod /dev/hdc b 22 0 . This didn't help one iota. I had a look at dmesg, but there was no mention of hdc in it. (It did mention hdg, hdh, where my main hard drives are (don't ask!)). Use /dev/sdc instead of /dev/hdc. I booted up in to the kernel, did # ls /dev/sd*, and the only things displayed were /dev/sda and /dev/sda1. That is the place where my USB stick gets mounted. The default in new kernels is to only use /dev/sd*. I'm totally confused. Doesn't sd* mean SCSI disk drive? When I was installing Gentoo from the CD, I had to mount my main hard drive as /dev/sdb5. When I built my own kernel, it needed /dev/hdh5. This seems crazy. Is it documented anywhere in Gentoo? -- Alan Mackenzie (Nuremberg, Germany).
Re: [gentoo-user] Re: mount: special device /dev/hdc does not exist. What does this mean?
Hi, Miernik, On Sat, Jul 19, 2008 at 09:13:09PM +0200, Miernik wrote: Alan Mackenzie [EMAIL PROTECTED] wrote: # mknod /dev/hdc b 22 0 This didn't help one iota. I had a look at dmesg, but there was no mention of hdc in it. (It did mention hdg, hdh, where my main hard drives are (don't ask!)). Maybe there was some /dev/sda /dev/sdb or something similar? There's /dev/sda and /dev/sda1, and no other /dev/sd*. That's where my UBS stick gets mounted. Why do you assume your drive is under /dev/hdx and not /dev/sdx ? Er, because it's an IDE drive, and on my old Debian system it appears at /dev/hdc. My HDD is at /dev/hdh on both old Debian and new Gentoo. When I do an lspci -v, on my Gentoo system, this shows up for hd[cd]: 00:07.1 IDE interface: VIA Technologies, Inc. VT82C586A/B/VT82C686/A/B/VT823x/A/C PIPC Bus Master IDE (rev 06) (prog-if 8a [Master SecP PriP]) Subsystem: VIA Technologies, Inc. VT82C586/B/VT82C686/A/B/VT8233/A/C/VT8235 PIPC Bus Master IDE Flags: bus master, medium devsel, latency 32 [virtual] Memory at 01f0 (32-bit, non-prefetchable) [size=8] [virtual] Memory at 03f0 (type 3, non-prefetchable) [size=1] [virtual] Memory at 0170 (32-bit, non-prefetchable) [size=8] [virtual] Memory at 0370 (type 3, non-prefetchable) [size=1] I/O ports at a400 [size=16] Capabilities: [c0] Power Management version 2 This suggests that the IDE controller has been initialised properly, but the kernel has ignored it. -- Miernik http://miernik.name/ -- Alan Mackenzie (Nuremberg, Germany)
Re: [gentoo-user] Re: mount: special device /dev/hdc does not exist. What does this mean?
Alan Mackenzie [EMAIL PROTECTED] writes: There's /dev/sda and /dev/sda1, and no other /dev/sd*. That's where my UBS stick gets mounted. What about any /dev/sr*?