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#1 2012-12-26 14:38:40

x33a
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Registered: 2009-08-15
Posts: 3,347
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[solved] Weird problem formatting a flash drive

Ok, here's a very interesting problem I have encountered.

I had installed the arch iso on a flash drive using dd a few days back. Today, I was trying to remove that and create a fat32 partition instead.

Gparted came up with the usual recursive partition found error. I clicked on ignore, created a new partition table on the drive and formatted it as fat32, which we'll refer to as sdc1.

While mounting the drive with udevil, i typed sdc instead of sdc1, and to my surprise it mounted as ARCH_201212!

I could list all the files and could even read the contents (of the few ascii files I tried).

I deleted the new fat32 (sdc1) partition with fdisk this time, and created a new partition table, but the same result!

Finally I did

# dd if=/dev/zero of=/dev/sdc bs=512 count=1

But still if I mount sdc, it mounts as ARCH_201212 ...

Currently, all the files are listable but are damaged except a few.

see

./arch/aitab: data
./arch/any/usr-share.fs.sfs: data
./arch/boot/i686/archiso.img: Amiga Workbench
./arch/boot/i686/vmlinuz: data
./arch/boot/memtest: data
./arch/boot/memtest.COPYING: data
./arch/boot/syslinux/archiso.cfg: data
./arch/boot/syslinux/archiso_head.cfg: data
./arch/boot/syslinux/archiso_pxe32.cfg: data
./arch/boot/syslinux/archiso_pxe64.cfg: data
./arch/boot/syslinux/archiso_pxe_32_inc.cfg: data
./arch/boot/syslinux/archiso_pxe_both_inc.cfg: data
./arch/boot/syslinux/archiso_pxe_choose.cfg: data
./arch/boot/syslinux/archiso_sys32.cfg: data
./arch/boot/syslinux/archiso_sys64.cfg: data
./arch/boot/syslinux/archiso_sys_32_inc.cfg: data
./arch/boot/syslinux/archiso_sys_both_inc.cfg: data
./arch/boot/syslinux/archiso_sys_choose.cfg: data
./arch/boot/syslinux/archiso_tail.cfg: data
./arch/boot/syslinux/cat.c32: data
./arch/boot/syslinux/chain.c32: data
./arch/boot/syslinux/cmd.c32: data
./arch/boot/syslinux/config.c32: data
./arch/boot/syslinux/cpuid.c32: data
./arch/boot/syslinux/cpuidtest.c32: data
./arch/boot/syslinux/disk.c32: data
./arch/boot/syslinux/dmitest.c32: data
./arch/boot/syslinux/elf.c32: data
./arch/boot/syslinux/ethersel.c32: data
./arch/boot/syslinux/gfxboot.c32: data
./arch/boot/syslinux/gpxecmd.c32: data
./arch/boot/syslinux/gpxelinux.0: data
./arch/boot/syslinux/gpxelinuxk.0: data
./arch/boot/syslinux/hdt/modalias.gz: data
./arch/boot/syslinux/hdt/pciids.gz: data
./arch/boot/syslinux/hdt.c32: data
./arch/boot/syslinux/host.c32: data
./arch/boot/syslinux/ifcpu.c32: data
./arch/boot/syslinux/ifcpu64.c32: data
./arch/boot/syslinux/ifmemdsk.c32: data
./arch/boot/syslinux/ifplop.c32: data
./arch/boot/syslinux/int18.com: data
./arch/boot/syslinux/kbdmap.c32: data
./arch/boot/syslinux/kontron_wdt.c32: data
./arch/boot/syslinux/linux.c32: data
./arch/boot/syslinux/ls.c32: data
./arch/boot/syslinux/lua.c32: data
./arch/boot/syslinux/mboot.c32: data
./arch/boot/syslinux/memdisk: data
./arch/boot/syslinux/memdump.com: data
./arch/boot/syslinux/meminfo.c32: data
./arch/boot/syslinux/menu.c32: data
./arch/boot/syslinux/pcitest.c32: data
./arch/boot/syslinux/pmload.c32: data
./arch/boot/syslinux/poweroff.com: data
./arch/boot/syslinux/prdhcp.c32: data
./arch/boot/syslinux/pwd.c32: data
./arch/boot/syslinux/pxechain.com: data
./arch/boot/syslinux/pxechn.c32: data
./arch/boot/syslinux/pxelinux.0: data
./arch/boot/syslinux/reboot.c32: data
./arch/boot/syslinux/rosh.c32: data
./arch/boot/syslinux/sanboot.c32: data
./arch/boot/syslinux/sdi.c32: data
./arch/boot/syslinux/splash.png: data
./arch/boot/syslinux/sysdump.c32: data
./arch/boot/syslinux/syslinux.cfg: data
./arch/boot/syslinux/syslinux.com: data
./arch/boot/syslinux/ver.com: data
./arch/boot/syslinux/vesainfo.c32: data
./arch/boot/syslinux/vesamenu.c32: data
./arch/boot/syslinux/vpdtest.c32: data
./arch/boot/syslinux/whichsys.c32: data
./arch/boot/syslinux/zzjson.c32: data
./arch/boot/x86_64/archiso.img: data
./arch/boot/x86_64/vmlinuz: data
./arch/checksum.i686.md5: data
./arch/checksum.x86_64.md5: data
./arch/i686/root-image.fs.sfs: data
./arch/i686/usr-lib-modules.fs.sfs: data
./arch/pkglist.i686.txt: data
./arch/pkglist.x86_64.txt: data
./arch/x86_64/root-image.fs.sfs: data
./arch/x86_64/usr-lib-modules.fs.sfs: data
./EFI/archiso/efiboot.img: data
./EFI/boot/bootx64.efi: data
./EFI/shellx64_v1.efi: MS-DOS executable
./EFI/shellx64_v2.efi: data
./isolinux/boot.cat: data
./isolinux/isohdpfx.bin: data
./isolinux/isolinux.bin: data
./isolinux/isolinux.cfg: data
./loader/entries/archiso-x86_64.conf: ASCII text
./loader/entries/uefi-shell-v1-x86_64.conf: data
./loader/entries/uefi-shell-v2-x86_64.conf: data
./loader/loader.conf: data

By the way, it is not an issue with the arch iso, as I have another flash drive with Linux mint, and it displays the same behaviour.

Has anyone experienced anything similar?

And more importantly how can I remove all traces of the previous data.

Last edited by x33a (2016-01-08 04:54:27)

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#2 2012-12-27 05:31:15

x33a
Forum Moderator
Registered: 2009-08-15
Posts: 3,347
Website

Re: [solved] Weird problem formatting a flash drive

So i decided to format the drive with windows 7, and another weird thing happened.

The Linux Mint drive was formatted successfully with windows 7 but again when i tried to mount the partition in arch, sdc1 mounted with the linux mint label! But the contents were blank. So, somehow the label persisted but everything else vanished.

As for the archlinux flash drive, it too formatted successfully with windows 7, but the partition table was all messed up. I formatted it with gparted and everything was fine again.

Anyway, I'll be sure to stay away from dd for installating any iso on a drive, especially for any drive I intend to use for data too.

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#3 2012-12-28 12:15:27

DSpider
Member
From: Romania
Registered: 2009-08-23
Posts: 2,273

Re: [solved] Weird problem formatting a flash drive

You're not the first one to notice this.

https://wiki.archlinux.org/index.php/Ta … afterwards


"How to Succeed with Linux"

I have made a personal commitment not to reply in topics that start with a lowercase letter. Proper grammar and punctuation is a sign of respect, and if you do not show any, you will NOT receive any help (at least not from me).

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#4 2012-12-29 07:25:45

x33a
Forum Moderator
Registered: 2009-08-15
Posts: 3,347
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Re: [solved] Weird problem formatting a flash drive

Nice to see that I am not alone tongue

Anyway, Rtfm13's solution sounds interesting, but it would unnecessarily reduce the life of the flash drive. Do you have any better idea?

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#5 2012-12-29 10:13:34

DSpider
Member
From: Romania
Registered: 2009-08-23
Posts: 2,273

Re: [solved] Weird problem formatting a flash drive

x33a wrote:

sounds interesting, but it would unnecessarily reduce the life of the flash drive.

You mean zeroing out more than just the first 512 bytes? That's not true. I think you're more likely to lose it or have it stolen before blocks would start to give out. 100.000-400.000 writes translate as 50-something years of normal usage. Don't worry about it.


"How to Succeed with Linux"

I have made a personal commitment not to reply in topics that start with a lowercase letter. Proper grammar and punctuation is a sign of respect, and if you do not show any, you will NOT receive any help (at least not from me).

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#6 2012-12-30 07:06:13

x33a
Forum Moderator
Registered: 2009-08-15
Posts: 3,347
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Re: [solved] Weird problem formatting a flash drive

I meant zeroing the whole drive, or equivalent to the size of the iso, as said by Rtfm13.

I finally just zeroed as much of the disk as I thought the ISO might have been written to.

That would shorten the lifespan i think.

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#7 2012-12-30 08:11:37

DSpider
Member
From: Romania
Registered: 2009-08-23
Posts: 2,273

Re: [solved] Weird problem formatting a flash drive

It doesn't. It's just like a normal write. It's as if you're filling the drive with various files, except that it's all 0's instead of random numbers. It counts as a single write (out of 100.000), which you'll never reach in 50 years; you'll replace it with a better or larger one in 5-7 years, or manage to somehow lose it by that time. Like I said, don't worry about it.

Even if you were to completely fill it up with data 100 times every day:

100 times each day * 30 days in a month = 3.000 writes

3.000 * 12 months in a year = 36.000 writes

So it would last about 3 years. But obviously, you're not writing it to every day, 100 times. Sometimes you're on holiday, sometimes you don't even boot up the computer, sometimes you're sick, etc. And you're also not filling it up completely, so there will be blocks that have barely been touched. Just don't set a swap file or browser cache or anything like that on it.


"How to Succeed with Linux"

I have made a personal commitment not to reply in topics that start with a lowercase letter. Proper grammar and punctuation is a sign of respect, and if you do not show any, you will NOT receive any help (at least not from me).

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#8 2012-12-30 19:02:17

x33a
Forum Moderator
Registered: 2009-08-15
Posts: 3,347
Website

Re: [solved] Weird problem formatting a flash drive

I rarely use it, so it should be fine. Thanks for the explanation.

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