dave_user
417
edits
Changes
no edit summary
[ <=> ] 652.482 694K/s
</syntaxhighlight>
=== Q: Buffer IO Error for uSD ===
When you try to write a large file on a micro SD, connected to the VM through an adapter, like the one shown in the image, it can happen that the system crashes.
[[File:Generic-card-reader.jpg|center|thumb|Generic Card Reader]]
In case of error, the kernel message that is printed is the following<syntaxhighlight lang="bash">
[ 358.392710] sdb: sdb1 sdb2
[ 880.588382] EXT4-fs (sdb2): mounting ext3 file system using the ext4 subsystem
[ 881.046203] EXT4-fs (sdb2): mounted filesystem with ordered data mode. Opts: (null)
[ 1008.759054] usb 1-1: USB disconnect, device number 2
[ 1008.778105] blk_update_request: I/O error, dev sdb, sector 19338752 op 0x1:(WRITE) flags 0x4000 phys_seg 14 prio class 0
[ 1008.778116] blk_update_request: I/O error, dev sdb, sector 19091736 op 0x1:(WRITE) flags 0x4800 phys_seg 30 prio class 0
[ 1008.778119] EXT4-fs warning (device sdb2): ext4_end_bio:311: I/O error 10 writing to inode 853990 (offset 0 size 0 starting block 2386468)
[ 1008.778121] Buffer I/O error on device sdb2, logical block 289315
[ 1008.778128] EXT4-fs warning (device sdb2): ext4_end_bio:311: I/O error 10 writing to inode 853990 (offset 0 size 0 starting block 2386469)
[ 1008.778128] Buffer I/O error on device sdb2, logical block 289316
[ 1008.778130] EXT4-fs warning (device sdb2): ext4_end_bio:311: I/O error 10 writing to inode 853990 (offset 0 size 0 starting block 2386470)
[ 1008.778130] Buffer I/O error on device sdb2, logical block 289317
[ 1008.778132] EXT4-fs warning (device sdb2): ext4_end_bio:311: I/O error 10 writing to inode 853990 (offset 0 size 0 starting block 2386471)
[ 1008.778133] Buffer I/O error on device sdb2, logical block 289318
[ 1008.778135] EXT4-fs warning (device sdb2): ext4_end_bio:311: I/O error 10 writing to inode 853990 (offset 0 size 0 starting block 2386472)
[ 1008.778136] Buffer I/O error on device sdb2, logical block 289319
[ 1008.778138] EXT4-fs warning (device sdb2): ext4_end_bio:311: I/O error 10 writing to inode 853990 (offset 0 size 0 starting block 2386473)
[ 1008.778138] Buffer I/O error on device sdb2, logical block 289320
[ 1008.778140] EXT4-fs warning (device sdb2): ext4_end_bio:311: I/O error 10 writing to inode 853990 (offset 0 size 0 starting block 2386474)
[ 1008.778140] Buffer I/O error on device sdb2, logical block 289321
[ 1008.778141] EXT4-fs warning (device sdb2): ext4_end_bio:311: I/O error 10 writing to inode 853990 (offset 0 size 0 starting block 2386475)
[ 1008.778142] Buffer I/O error on device sdb2, logical block 289322
[ 1008.778144] EXT4-fs warning (device sdb2): ext4_end_bio:311: I/O error 10 writing to inode 853990 (offset 0 size 0 starting block 2386476)
[ 1008.778144] Buffer I/O error on device sdb2, logical block 289323
[ 1008.778146] EXT4-fs warning (device sdb2): ext4_end_bio:311: I/O error 10 writing to inode 853990 (offset 0 size 0 starting block 2386477)
[ 1008.778146] Buffer I/O error on device sdb2, logical block 289324
[ 1008.778208] blk_update_request: I/O error, dev sdb, sector 19338992 op 0x1:(WRITE) flags 0x0 phys_seg 1 prio class 0
[ 1008.778222] blk_update_request: I/O error, dev sdb, sector 19358224 op 0x1:(WRITE) flags 0x0 phys_seg 11 prio class 0
[ 1008.778262] blk_update_request: I/O error, dev sdb, sector 19091976 op 0x1:(WRITE) flags 0x4800 phys_seg 30 prio class 0
[ 1008.778282] blk_update_request: I/O error, dev sdb, sector 19092216 op 0x1:(WRITE) flags 0x4800 phys_seg 30 prio class 0
[ 1008.778317] blk_update_request: I/O error, dev sdb, sector 44090904 op 0x1:(WRITE) flags 0x0 phys_seg 10 prio class 0
[ 1008.778325] blk_update_request: I/O error, dev sdb, sector 19092456 op 0x1:(WRITE) flags 0x4800 phys_seg 30 prio class 0
[ 1008.778356] blk_update_request: I/O error, dev sdb, sector 19339136 op 0x1:(WRITE) flags 0x0 phys_seg 8 prio class 0
[ 1008.778364] blk_update_request: I/O error, dev sdb, sector 19358464 op 0x1:(WRITE) flags 0x4000 phys_seg 15 prio class 0
[ 1008.778423] EXT4-fs error (device sdb2): ext4_wait_block_bitmap:519: comm tar: Cannot read block bitmap - block_group = 13, block_bitmap = 425984
[ 1008.778456] Buffer I/O error on dev sdb2, logical block 0, lost sync page write
[ 1008.778458] EXT4-fs (sdb2): I/O error while writing superblock
[ 1008.778558] EXT4-fs error (device sdb2): ext4_wait_block_bitmap:519: comm tar: Cannot read block bitmap - block_group = 14, block_bitmap = 458752
[ 1008.778615] Buffer I/O error on dev sdb2, logical block 0, lost sync page write
[ 1008.778617] EXT4-fs (sdb2): I/O error while writing superblock
[ 1008.778626] EXT4-fs error (device sdb2): ext4_wait_block_bitmap:519: comm tar: Cannot read block bitmap - block_group = 15, block_bitmap = 491520
[ 1008.778677] Buffer I/O error on dev sdb2, logical block 0, lost sync page write
[ 1008.778678] EXT4-fs (sdb2): I/O error while writing superblock
[ 1008.778686] EXT4-fs error (device sdb2): ext4_wait_block_bitmap:519: comm tar: Cannot read block bitmap - block_group = 16, block_bitmap = 524288
[ 1008.778735] Buffer I/O error on dev sdb2, logical block 0, lost sync page write
[ 1008.778737] EXT4-fs (sdb2): I/O error while writing superblock
[ 1008.778744] EXT4-fs error (device sdb2): ext4_wait_block_bitmap:519: comm tar: Cannot read block bitmap - block_group = 17, block_bitmap = 557056
[ 1008.778826] Buffer I/O error on dev sdb2, logical block 0, lost sync page write
[ 1008.778828] EXT4-fs (sdb2): I/O error while writing superblock
[ 1008.839764] Buffer I/O error on dev sdb2, logical block 131072, lost async page write
[ 1008.839769] Buffer I/O error on dev sdb2, logical block 164865, lost async page write
[ 1008.839776] Buffer I/O error on dev sdb2, logical block 196608, lost async page write
[ 1008.839778] Buffer I/O error on dev sdb2, logical block 230401, lost async page write
[ 1008.839795] Buffer I/O error on dev sdb2, logical block 2818048, lost async page write
[ 1008.841976] JBD2: Detected IO errors while flushing file data on sdb2-8
[ 1008.842006] Aborting journal on device sdb2-8.
[ 1008.842011] JBD2: Error -5 detected when updating journal superblock for sdb2-8.
[ 1008.842130] JBD2: Detected IO errors while flushing file data on sdb2-8
[ 1008.851777] EXT4-fs (sdb2): I/O error while writing superblock
[ 1008.851780] EXT4-fs error (device sdb2): ext4_journal_check_start:61: Detected aborted journal
[ 1008.851780] EXT4-fs (sdb2): Remounting filesystem read-only
[ 1008.921620] JBD2: Error while async write back metadata bh 131072.
[ 1008.921621] JBD2: Error while async write back metadata bh 164865.
[ 1008.921624] JBD2: Error while async write back metadata bh 196608.
[ 1008.921649] JBD2: Error while async write back metadata bh 230401.
[ 1008.921864] JBD2: Error while async write back metadata bh 2818048.
[ 1008.922181] JBD2: Error while async write back metadata bh 2818637.
...
[ 1008.924465] JBD2: Error while async write back metadata bh 3408720.
[ 1008.924467] JBD2: Error while async write back metadata bh 3408721.
[ 1009.027187] EXT4-fs error (device sdb2): ext4_wait_block_bitmap:519: comm tar: Cannot read block bitmap - block_group = 12, block_bitmap = 393216
[ 1009.027191] EXT4-fs error (device sdb2): ext4_discard_preallocations:4113: comm tar: Error -5 reading block bitmap for 12
[ 1009.027193] EXT4-fs error (device sdb2): ext4_wait_block_bitmap:519: comm tar: Cannot read block bitmap - block_group = 12, block_bitmap = 393216
[ 1009.027194] EXT4-fs error (device sdb2): ext4_discard_preallocations:4113: comm tar: Error -5 reading block bitmap for 12
[ 1009.027200] EXT4-fs error (device sdb2): ext4_wait_block_bitmap:519: comm tar: Cannot read block bitmap - block_group = 18, block_bitmap = 589824
[ 1014.162995] EXT4-fs error: 30 callbacks suppressed
[ 1014.162997] EXT4-fs error (device sdb2): __ext4_find_entry:1577: inode #819201: comm tar: reading directory lblock 0
[ 1014.163016] EXT4-fs error (device sdb2): __ext4_find_entry:1577: inode #819201: comm tar: reading directory lblock 0
[ 1014.163160] EXT4-fs error (device sdb2): __ext4_find_entry:1577: inode #819201: comm tar: reading directory lblock 0
[ 1014.163163] EXT4-fs error (device sdb2): __ext4_find_entry:1577: inode #819201: comm tar: reading directory lblock 0
[ 1014.163178] EXT4-fs error (device sdb2): __ext4_find_entry:1577: inode #819201: comm tar: reading directory lblock 0
[ 1014.163181] EXT4-fs error (device sdb2): __ext4_find_entry:1577: inode #819201: comm tar: reading directory lblock 0
[ 1014.163192] EXT4-fs error (device sdb2): __ext4_find_entry:1577: inode #819201: comm tar: reading directory lblock 0
[ 1014.163194] EXT4-fs error (device sdb2): __ext4_find_entry:1577: inode #819201: comm tar: reading directory lblock 0
[ 1014.163204] EXT4-fs error (device sdb2): __ext4_find_entry:1577: inode #819201: comm tar: reading directory lblock 0
[ 1014.163207] EXT4-fs error (device sdb2): __ext4_find_entry:1577: inode #819201: comm tar: reading directory lblock 0
[ 1020.736540] EXT4-fs error: 4649 callbacks suppressed
[ 1020.736541] EXT4-fs error (device sdb2): __ext4_find_entry:1577: inode #819201: comm tar: reading directory lblock 0
[ 1020.736679] EXT4-fs error (device sdb2): __ext4_find_entry:1577: inode #819201: comm tar: reading directory lblock 0
[ 1020.736707] EXT4-fs error (device sdb2): __ext4_find_entry:1577: inode #819201: comm tar: reading directory lblock 0
[ 1020.736733] EXT4-fs error (device sdb2): __ext4_find_entry:1577: inode #819201: comm tar: reading directory lblock 0
[ 1020.736741] EXT4-fs error (device sdb2): __ext4_find_entry:1577: inode #819201: comm tar: reading directory lblock 0
[ 1020.736909] EXT4-fs error (device sdb2): __ext4_find_entry:1577: inode #819201: comm tar: reading directory lblock 0
[ 1020.736917] EXT4-fs error (device sdb2): __ext4_find_entry:1577: inode #819201: comm tar: reading directory lblock 0
[ 1020.736946] EXT4-fs error (device sdb2): __ext4_find_entry:1577: inode #819201: comm tar: reading directory lblock 0
[ 1020.736955] EXT4-fs error (device sdb2): __ext4_find_entry:1577: inode #819201: comm tar: reading directory lblock 0
[ 1020.737113] EXT4-fs error (device sdb2): __ext4_find_entry:1577: inode #819201: comm tar: reading directory lblock 0
[ 1022.476182] EXT4-fs warning: 33909 callbacks suppressed
[ 1022.476184] EXT4-fs warning (device sdb2): dx_probe:786: inode #851989: lblock 0: comm tar: error -5 reading directory block
[ 1022.476187] EXT4-fs warning (device sdb2): dx_probe:786: inode #851989: lblock 0: comm tar: error -5 reading directory block
[ 1022.476189] EXT4-fs warning (device sdb2): dx_probe:786: inode #851989: lblock 0: comm tar: error -5 reading directory block
[ 1022.476192] EXT4-fs warning (device sdb2): dx_probe:786: inode #851989: lblock 0: comm tar: error -5 reading directory block
[ 1022.476193] EXT4-fs warning (device sdb2): dx_probe:786: inode #851989: lblock 0: comm tar: error -5 reading directory block
[ 1022.476196] EXT4-fs warning (device sdb2): dx_probe:786: inode #851989: lblock 0: comm tar: error -5 reading directory block
[ 1022.476198] EXT4-fs warning (device sdb2): dx_probe:786: inode #851989: lblock 0: comm tar: error -5 reading directory block
[ 1022.476200] EXT4-fs warning (device sdb2): dx_probe:786: inode #851989: lblock 0: comm tar: error -5 reading directory block
[ 1022.476202] EXT4-fs warning (device sdb2): dx_probe:786: inode #851989: lblock 0: comm tar: error -5 reading directory block
[ 1022.476204] EXT4-fs warning (device sdb2): dx_probe:786: inode #851989: lblock 0: comm tar: error -5 reading directory block
</syntaxhighlight>To avoid this problem, it is recommended to change the micro SD card reader, and then choose a more robust one.