Messages in this thread | | | From | "Khimenko Victor" <> | Date | Sun, 20 Dec 1998 23:03:24 +0300 (MSK) | Subject | mk2efs could format disk ??? (wa Re: LS-120 Formatting?) |
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In <Pine.LNX.3.96.981220183505.1172A-100000@ps.cus.umist.ac.uk> Riley Williams (rhw@bigfoot.com) wrote: RW> Hi there.
RW> ===8<=== Lots of unnecessary insults omitted ===>8===
>>>> Great. Now take 1.88Mb floppy (maked with xdfcopy) and explain >>>> how to create standard 1.44Mb floppy with mkfs.ext2 :-))
>>> mke2fs /dev/fd0H1440
>> Yes, really ?
RW> Yep...
Try before claim such things. 1.88Mb format is NOT compatible with any standard format on low level (there are 1K sectors to start with :-). So mk2efs will hanghs exactly the same way as in my experiment. fdformat will work of course.
>>>> Format under DOS will do this quite happily.
>>> Why bother with DOS ???
>>>> Or even simpler: take 1.44Mb floppy and make 720Kb floppy from >>>> it (this is safe).
>>> mke2fs /dev/fd0D720
>> Are you sure ? What about 5" 720K disks ? A have few 5" 1440Kb >> disks and 720Kb disks :-))
RW> 5" 720k disks can be had with /dev/fd?h720 without problem. 5" 1440k RW> disks are not one of the standard formats supported by Linux...
I have 5" 1440k disks and I'm could mount them as /dev/fd1H1440 just fine. mke2fs works with them just fine if I use /dev/fd1H1440 and does not work when I refer them as /dev/fd1h1200 !!! BTW 5" 720k disks could be ACCESSED with /dev/fd?h720 but NOT CREATED from 360k or 1.2M disks not via fdformat /dev/fd?h720 nor with mke2fs /dev/fd?h720 !!! Both commands will just hungs !
RW> Incidentally, my understanding as to why these work when using RW> /dev/fd0 doesnae is because the suffixed versions over-ride the RW> drive's own details and return their own...
Yes, suffixed version just says: "no, autodect will fail for this drive -- do not try it". Suffixed version could not magically reformat drive (fdformat could and here suffixed versions are helpful since autodetect will fail here :-) but could just say to kernel: "no there are not 18 sectors for track but only 9". Kernel will happily use only 9 first sectors then. Floppy will look like 720K floppy afterwards but still there are will be 18 sectors for each track (9 of them not used). This is not a case for 1.88Mb drive vs 1.44Mb drive (different sector sizes) nor for 1.2Mb drive vs 360K drive (different number of tracks).
>>> I regularly do the latter, and have never had any problems with >>> it...
>>>> Again format under DOS will do this just fine.
>>> Again, why bother with DOS ???
>> Since in DOS low-level format and filesystem creation is combined >> in one program unlike Linux.
RW> True, but irrelevant...
VERY RELEVANT -- see below. DOS format could change format of media if needed. mke2fs COULD NOT ! NEVER ! Interpretation of format for already formatted media could be changed (sometimes successfull, sometimes not) but reformating will NEVER occurs.
>>>> PS. May be you have specially modified mkfs.ext2 which could do >>>> low-level format but standard mkfs.ext2 will do just it: >>>> create ext2fs filesystem on low-level formatted driver.
>>> If I do, then RedHat have been supplying a patched version since >>> at least RedHat 4.1 when I started with Linux - I've been doing >>> the above since then...
>> I'm just checked with RedHat 5.1 :-))
RW> Please advise re your findings...
>>> For reference, from this system:
>> Q>> $ ls -lFG /dev/fd0* >> Q>> brw-rw-r-- 1 root 2, 0 May 5 1998 /dev/fd0 >> Q>> brw-rw-r-- 1 root 2, 12 May 5 1998 /dev/fd0D360 >> Q>> brw-rw-r-- 1 root 2, 16 May 5 1998 /dev/fd0D720 >> Q>> brw-rw-r-- 1 root 2, 28 May 5 1998 /dev/fd0H1440 >> Q>> brw-rw-r-- 1 root 2, 12 May 5 1998 /dev/fd0H360 >> Q>> brw-rw-r-- 1 root 2, 16 May 5 1998 /dev/fd0H720 >> Q>> brw-rw-r-- 1 root 2, 4 May 5 1998 /dev/fd0d360 >> Q>> brw-rw-r-- 1 root 2, 8 May 5 1998 /dev/fd0h1200 >> Q>> brw-rw-r-- 1 root 2, 20 May 5 1998 /dev/fd0h360 >> Q>> brw-rw-r-- 1 root 2, 24 May 5 1998 /dev/fd0h720 >> Q>> $
>> Ok. Just tried to use your braindead "theory" :
RW> ===8<=== Lots more rubbish omitted, relevant lines retained ===>8===
>> [root@localhost /root]# fdformat /dev/fd1h1200 >> [root@localhost /root]# mke2fs /dev/fd1h360
>> RedHat 5.1, /dev/fd1 -- 5" floppy drive, more information available >> by request.
>> Why mke2fs works just fine after fdformat /dev/fd1h360 but not >> after fdformat /dev/fd1h1200 ?
RW> Probably because those two are NOT compatible with each other.
Yes. It was EXACTLY what I'm want: two DIFFERENT, INCOMPATIBLE formats but for the same physical media ! This is needed as countersample for your stupid theory about magic format while mke2fs ...
RW> Try using the compatible options, which have been working fine for me for RW> OVER TWO YEARS...and if they're not working for you, then either RW> you've patched the kernel to prevent them from doing so, somebody else RW> has done so, or the relevant entries in /dev have the wrong mknod RW> numbers attached to them...
Yes, I know. But this will not prove ANYTHING about initial claim !!! If there are compatible options then reformating is not needed !
RW> For reference, your second line should refer to
Q>> /dev/fd1d360 Q>> ^
RW> As I understand it, /dev/fd1h360 refers to a drive formatted as SINGLE RW> sided, 80 tracks, 9 sectors per track, but I have never found a drive RW> where it could be used...
You are joking. Yet again: -- cut -- [root@localhost /root]# fdformat /dev/fd1h360 Double-sided, 40 tracks, 9 sec/track. Total capacity 360 kB. Formatting ... done Verifying ... done -- cut -- What's the difference between /dev/fd?h360 and /dev/fd?d360 ??? You are joking ! This is just mean: high-density floppy formatted for 360k and double-density drive formatted for 360k !!! (Why the difference ? Oh. Long story. There are difference in coercive force for different types of floppies :-)
Just standard 2.0.34 kernel from RedHat 5.1 (I'm use some 2.1.x kernel usually but specially for testing I'm reboted with this old one :-)
Here was you point: mk2efs could format drive. This is HORRIBLE wrong. I am have physical media (5" disk :-) which could be formatted by two different incompatible low-level format versions: as h1200 and as h360 (d360 will work as well -- just information will be kept safely on disk for less time :-). If mk2efs could format media (this was your initial claim and start of discussion) then this should not lead to any problems. This is not a case: if disk is formatted as h360 (via fdformat) mke2fs works, if disk is formatted as h1200 (via fdformat) then mke2fs hangs horrible. What this means ? Just one thing: mke2fs will not format disk ! NEVER !
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