Arch Linux

Suresh Soundararajan

Member

Registered: 2025-08-03

Posts: 3

SD card shows I/O errors at sector 0 — cannot format in Arch Linux

Hi Arch users,

I have a 59.4 GB SD card that I cannot format in Arch Linux — tools like

wipefs

,

mkfs.vfat

, and GParted fail with I/O errors.

System info

• OS: Arch Linux x86_64

• SD card reader: SanDisk SDCARD

Problem description
When I try to format

/dev/sdb

, I get:

sudo wipefs -a /dev/sdb
wipefs: /dev/sdb: failed to erase dos magic string at offset 0x000001fe: Input/output error

lsblk output

NAME        MAJ:MIN RM   SIZE RO TYPE MOUNTPOINTS
sdb           8:16   1  59.4G  0 disk

hdparm output

$ sudo hdparm -r /dev/sdb

/dev/sdb:
 readonly = 0 (off)

dmesg tail after trying to write

[ 1926.190613] I/O error, dev sdb, sector 0 op 0x1:(WRITE) flags 0x800
[ 1926.202642] unable to read partition table

I also tried

ddrescue

to recover data, but sector 0 immediately fails.

Additional info

• The card was previously formatted successfully in my Android phone and worked for a while.

• Now, it fails to format on PC, but still formats successfully on my phone.

Question:
Is there any way to force-repair or remap sector 0 in Arch Linux, or is the card permanently damaged and only replaceable?

Thanks in advance.

seth

Member

From: Won't reply 2 private help req

Registered: 2012-09-03

Posts: 75,177

Re: SD card shows I/O errors at sector 0 — cannot format in Arch Linux

Do you have access to another card reader?

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Suresh Soundararajan

Member

Registered: 2025-08-03

Posts: 3

Re: SD card shows I/O errors at sector 0 — cannot format in Arch Linux

Do you have access to another card reader?

Thanks for your reply.

I found that the SD card itself is working fine in both my phone and laptop as long as it is formatted as exFAT. The problem only happens when I try to reformat it to FAT32 or any other filesystem/partition type — I get the same I/O error in Arch Linux.

The reason I’m trying to reformat is because my Micromax TV doesn’t support exFAT, only FAT32. I also tried making the SD card bootable (flashing an ISO), but that fails with the same error.

So the situation is:

exFAT format: works perfectly on phone and laptop

FAT32/bootable format: fails with I/O error in Arch Linux

I need FAT32 for TV compatibility and for making the card bootable

Is there any known way to fully erase/repartition such a card in Linux when sector 0 errors appear, or is this a sign that the card is partially failing?

seth

Member

From: Won't reply 2 private help req

Registered: 2012-09-03

Posts: 75,177

Re: SD card shows I/O errors at sector 0 — cannot format in Arch Linux

Just to be clear: the card reads and writes fine but you've so far not been able to write sector 0 on any system?
(Specifically testing a different card reader)

Can you write the MBR on other SD cards in that reader w/o problems?
Have you researched the specific card? The vendor might have fused the MBR, but

I also tried ddrescue to recover data, but sector 0 immediately fails.

sounds concerning - is that only after trying to write the sector? How can you use the card at all if you cannot access the MBR?

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