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I have an embedded PC (based on Atom Z3735F with a 32 GB eMMC for o.s.) that I use as NAS with OpenMediaVault 4.1.2-1. On an USB port I connected a 1 TB Hard-disk for storage.

Whenever I do something that require "quite" high amount of data exchanged with the disk it disconnects. Some examples:

  • zip a large folder on the disk (> 500 MB)
  • download a single large folder (> 200 MB)
  • download a lot of small files (> 1000)

Of course the numbers are just an estimate to understand what I mean. I cannot measure them precisely.

When it happens the disk isn't visible anymore from the network because it will be remounted to /dev/sdb instead of /dev/sda. I catch the dmesg output. I hope it might be useful to understand where is the problem:

[517315.070064] sd 0:0:0:0: [sda] tag#0 uas_eh_abort_handler 0 uas-tag 1 inflight: CMD
[517315.070087] sd 0:0:0:0: [sda] tag#0 CDB: Read(10) 28 00 00 dd 1c 00 00 00 80 00
[517318.131244] sd 0:0:0:0: [sda] tag#1 uas_eh_abort_handler 0 uas-tag 2 inflight: CMD
[517318.131268] sd 0:0:0:0: [sda] tag#1 CDB: Write(10) 2a 00 02 1f c8 00 00 04 00 00
[517318.131294] scsi host0: uas_eh_bus_reset_handler start
[517318.131359] usb 1-2.1: cmd cmplt err -2
[517318.131719] usb 1-2.1: cmd cmplt err -2
[517318.132050] usb 1-2.1: cmd cmplt err -2
[517318.132384] usb 1-2.1: cmd cmplt err -2
[517318.132710] usb 1-2.1: cmd cmplt err -2
[517318.133041] usb 1-2.1: cmd cmplt err -2
[517318.134049] sd 0:0:0:0: [sda] tag#2 uas_zap_pending 0 uas-tag 3 inflight: CMD
[517318.134067] sd 0:0:0:0: [sda] tag#2 CDB: Write(10) 2a 00 3a 04 20 c8 00 00 20 00
[517318.134088] sd 0:0:0:0: [sda] tag#3 uas_zap_pending 0 uas-tag 4 inflight: CMD
[517318.134103] sd 0:0:0:0: [sda] tag#3 CDB: Read(10) 28 00 00 dd 1c 80 00 02 00 00
[517318.134123] sd 0:0:0:0: [sda] tag#4 uas_zap_pending 0 uas-tag 5 inflight: CMD
[517318.134137] sd 0:0:0:0: [sda] tag#4 CDB: Read(10) 28 00 00 dd 1f 80 00 01 00 00
[517318.134157] sd 0:0:0:0: [sda] tag#5 uas_zap_pending 0 uas-tag 6 inflight: CMD
[517318.134171] sd 0:0:0:0: [sda] tag#5 CDB: Read(10) 28 00 00 dd 1e 80 00 01 00 00
[517318.134191] sd 0:0:0:0: [sda] tag#6 uas_zap_pending 0 uas-tag 7 inflight: CMD
[517318.134204] sd 0:0:0:0: [sda] tag#6 CDB: Read(10) 28 00 00 dd 20 80 00 01 00 00
[517318.134224] sd 0:0:0:0: [sda] tag#7 uas_zap_pending 0 uas-tag 8 inflight: CMD
[517318.134238] sd 0:0:0:0: [sda] tag#7 CDB: Read(10) 28 00 00 dd 22 80 00 01 00 00
[517318.134257] sd 0:0:0:0: [sda] tag#8 uas_zap_pending 0 uas-tag 9 inflight: CMD
[517318.134271] sd 0:0:0:0: [sda] tag#8 CDB: Read(10) 28 00 00 dd 23 80 00 01 00 00
[517318.134291] sd 0:0:0:0: [sda] tag#9 uas_zap_pending 0 uas-tag 10 inflight: CMD
[517318.134305] sd 0:0:0:0: [sda] tag#9 CDB: Read(10) 28 00 00 dd 24 80 00 01 00 00
[517318.134325] sd 0:0:0:0: [sda] tag#10 uas_zap_pending 0 uas-tag 11 inflight: CMD
[517318.134339] sd 0:0:0:0: [sda] tag#10 CDB: Read(10) 28 00 00 dd 25 80 00 01 00 00
[517318.134359] sd 0:0:0:0: [sda] tag#11 uas_zap_pending 0 uas-tag 12 inflight: CMD
[517318.134372] sd 0:0:0:0: [sda] tag#11 CDB: Read(10) 28 00 00 dd 26 80 00 02 00 00
[517318.134392] sd 0:0:0:0: [sda] tag#12 uas_zap_pending 0 uas-tag 13 inflight: CMD
[517318.134406] sd 0:0:0:0: [sda] tag#12 CDB: Read(10) 28 00 00 dd 21 80 00 01 00 00
[517318.134426] sd 0:0:0:0: [sda] tag#13 uas_zap_pending 0 uas-tag 14 inflight: CMD
[517318.134439] sd 0:0:0:0: [sda] tag#13 CDB: Read(10) 28 00 00 dd 28 80 00 01 00 00
[517318.134459] sd 0:0:0:0: [sda] tag#14 uas_zap_pending 0 uas-tag 15 inflight: CMD
[517318.134473] sd 0:0:0:0: [sda] tag#14 CDB: Read(10) 28 00 00 dd 19 b8 00 00 48 00
[517318.134493] sd 0:0:0:0: [sda] tag#15 uas_zap_pending 0 uas-tag 16 inflight: CMD
[517318.134507] sd 0:0:0:0: [sda] tag#15 CDB: Write(10) 2a 00 02 1f cc 00 00 04 00 00
[517318.215359] usb 1-2.1: reset high-speed USB device number 3 using xhci_hcd
[517318.295250] usb 1-2.1: device descriptor read/64, error -71
[517318.483314] usb 1-2.1: device descriptor read/64, error -71
[517318.671386] usb 1-2.1: reset high-speed USB device number 3 using xhci_hcd
[517318.751402] usb 1-2.1: device descriptor read/64, error -71
[517318.939493] usb 1-2.1: device descriptor read/64, error -71
[517319.127565] usb 1-2.1: reset high-speed USB device number 3 using xhci_hcd
[517319.127681] usb 1-2.1: Device not responding to setup address.
[517319.335696] usb 1-2.1: Device not responding to setup address.
[517319.543685] usb 1-2.1: device not accepting address 3, error -71
[517319.623988] usb 1-2.1: reset high-speed USB device number 3 using xhci_hcd
[517319.624096] usb 1-2.1: Device not responding to setup address.
[517319.832253] usb 1-2.1: Device not responding to setup address.
[517320.040104] usb 1-2.1: device not accepting address 3, error -71
[517320.040693] scsi host0: uas_eh_bus_reset_handler FAILED err -19
[517320.040709] sd 0:0:0:0: Device offlined - not ready after error recovery
[517320.040721] sd 0:0:0:0: Device offlined - not ready after error recovery
[517320.040731] sd 0:0:0:0: Device offlined - not ready after error recovery
[517320.040741] sd 0:0:0:0: Device offlined - not ready after error recovery
[517320.040751] sd 0:0:0:0: Device offlined - not ready after error recovery
[517320.040761] sd 0:0:0:0: Device offlined - not ready after error recovery
[517320.040771] sd 0:0:0:0: Device offlined - not ready after error recovery
[517320.040781] sd 0:0:0:0: Device offlined - not ready after error recovery
[517320.040791] sd 0:0:0:0: Device offlined - not ready after error recovery
[517320.040801] sd 0:0:0:0: Device offlined - not ready after error recovery
[517320.040810] sd 0:0:0:0: Device offlined - not ready after error recovery
[517320.040820] sd 0:0:0:0: Device offlined - not ready after error recovery
[517320.040830] sd 0:0:0:0: Device offlined - not ready after error recovery
[517320.040840] sd 0:0:0:0: Device offlined - not ready after error recovery
[517320.040850] sd 0:0:0:0: Device offlined - not ready after error recovery
[517320.040860] sd 0:0:0:0: Device offlined - not ready after error recovery
[517320.041056] sd 0:0:0:0: [sda] tag#1 FAILED Result: hostbyte=DID_TIME_OUT driverbyte=DRIVER_OK
[517320.041075] sd 0:0:0:0: [sda] tag#1 CDB: Write(10) 2a 00 02 1f c8 00 00 04 00 00
[517320.041085] blk_update_request: I/O error, dev sda, sector 35637248
[517320.041546] sd 0:0:0:0: rejecting I/O to offline device
[517320.041902] sd 0:0:0:0: [sda] killing request
[517320.041920] sd 0:0:0:0: rejecting I/O to offline device
[517320.041959] sd 0:0:0:0: [sda] FAILED Result: hostbyte=DID_NO_CONNECT driverbyte=DRIVER_OK
[517320.041977] sd 0:0:0:0: [sda] CDB: Write(10) 2a 00 3a 04 20 c8 00 00 20 00
[517320.041988] blk_update_request: I/O error, dev sda, sector 973349064
[517320.042673] sd 0:0:0:0: [sda] killing request
[517320.042700] sd 0:0:0:0: rejecting I/O to offline device
[517320.043051] sd 0:0:0:0: [sda] killing request
[517320.043064] sd 0:0:0:0: rejecting I/O to offline device
[517320.043410] sd 0:0:0:0: [sda] killing request
[517320.043425] sd 0:0:0:0: rejecting I/O to offline device
[517320.043769] sd 0:0:0:0: [sda] killing request
[517320.043782] sd 0:0:0:0: rejecting I/O to offline device
[517320.044126] sd 0:0:0:0: [sda] killing request
[517320.044139] sd 0:0:0:0: rejecting I/O to offline device
[517320.044483] sd 0:0:0:0: [sda] killing request
[517320.044496] sd 0:0:0:0: rejecting I/O to offline device
[517320.044840] sd 0:0:0:0: [sda] killing request
[517320.044852] sd 0:0:0:0: rejecting I/O to offline device
[517320.045196] sd 0:0:0:0: [sda] killing request
[517320.045209] sd 0:0:0:0: rejecting I/O to offline device
[517320.045552] sd 0:0:0:0: [sda] killing request
[517320.045565] sd 0:0:0:0: rejecting I/O to offline device
[517320.045910] sd 0:0:0:0: [sda] killing request
[517320.045924] sd 0:0:0:0: rejecting I/O to offline device
[517320.046268] sd 0:0:0:0: [sda] killing request
[517320.046281] sd 0:0:0:0: rejecting I/O to offline device
[517320.046625] sd 0:0:0:0: [sda] killing request
[517320.046638] sd 0:0:0:0: rejecting I/O to offline device
[517320.046982] sd 0:0:0:0: [sda] killing request
[517320.047074] sd 0:0:0:0: [sda] tag#0 FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_TIMEOUT
[517320.047089] sd 0:0:0:0: [sda] FAILED Result: hostbyte=DID_NO_CONNECT driverbyte=DRIVER_OK
[517320.047113] sd 0:0:0:0: [sda] FAILED Result: hostbyte=DID_NO_CONNECT driverbyte=DRIVER_OK
[517320.047119] sd 0:0:0:0: [sda] CDB: Read(10) 28 00 00 dd 21 80 00 01 00 00
[517320.047132] sd 0:0:0:0: [sda] tag#0 CDB: Read(10) 28 00 00 dd 1c 00 00 00 80 00
[517320.047140] blk_update_request: I/O error, dev sda, sector 14492032
[517320.047168] blk_update_request: I/O error, dev sda, sector 14490624
[517320.047266] sd 0:0:0:0: [sda] FAILED Result: hostbyte=DID_NO_CONNECT driverbyte=DRIVER_OK
[517320.047285] sd 0:0:0:0: [sda] CDB: Write(10) 2a 00 02 1f cc 00 00 04 00 00
[517320.047299] blk_update_request: I/O error, dev sda, sector 35638272
[517320.047305] sd 0:0:0:0: [sda] FAILED Result: hostbyte=DID_NO_CONNECT driverbyte=DRIVER_OK
[517320.047327] EXT4-fs warning (device sda1): ext4_end_bio:314: I/O error -5 writing to inode 57934250 (offset 268435456 size 3117056 starting block 4454912)
[517320.047340] sd 0:0:0:0: [sda] CDB: Read(10) 28 00 00 dd 1c 80 00 02 00 00
[517320.047346] Buffer I/O error on device sda1, logical block 4454400
[517320.047361] blk_update_request: I/O error, dev sda, sector 14490752
[517320.047388] Buffer I/O error on device sda1, logical block 4454401
[517320.047400] Buffer I/O error on device sda1, logical block 4454402
[517320.047411] Buffer I/O error on device sda1, logical block 4454403
[517320.047423] Buffer I/O error on device sda1, logical block 4454404
[517320.047449] Buffer I/O error on device sda1, logical block 4454405
[517320.047460] Buffer I/O error on device sda1, logical block 4454406
[517320.047472] Buffer I/O error on device sda1, logical block 4454407
[517320.047484] sd 0:0:0:0: [sda] FAILED Result: hostbyte=DID_NO_CONNECT driverbyte=DRIVER_OK
PuTTYPuTTYPuTTYPuTTY[517320.047490] Buffer I/O error on device sda1, logical block 4454408
[517320.047501] sd 0:0:0:0: [sda] CDB: Read(10) 28 00 00 dd 1f 80 00 01 00 00
[517320.047507] Buffer I/O error on device sda1, logical block 4454409
[517320.047521] blk_update_request: I/O error, dev sda, sector 14491520
[517320.047602] sd 0:0:0:0: [sda] FAILED Result: hostbyte=DID_NO_CONNECT driverbyte=DRIVER_OK
[517320.047621] sd 0:0:0:0: [sda] CDB: Read(10) 28 00 00 dd 22 80 00 01 00 00
[517320.047634] blk_update_request: I/O error, dev sda, sector 14492288
[517320.047717] sd 0:0:0:0: [sda] FAILED Result: hostbyte=DID_NO_CONNECT driverbyte=DRIVER_OK
[517320.047736] sd 0:0:0:0: [sda] CDB: Read(10) 28 00 00 dd 24 80 00 01 00 00
[517320.047749] blk_update_request: I/O error, dev sda, sector 14492800
[517320.047849] blk_update_request: I/O error, dev sda, sector 14493056
[517320.048030] sd 0:0:0:0: rejecting I/O to offline device
[517320.048089] sd 0:0:0:0: rejecting I/O to offline device
[517320.048292] usb 1-2.1: USB disconnect, device number 3
[517320.048317] sd 0:0:0:0: rejecting I/O to offline device
[517320.048375] sd 0:0:0:0: rejecting I/O to offline device
[517320.048402] EXT4-fs warning (device sda1): ext4_end_bio:314: I/O error -5 writing to inode 57934250 (offset 268435456 size 3117056 starting block 4455168)
[517320.051803] EXT4-fs error (device sda1): ext4_wait_block_bitmap:503: comm kworker/u8:2: Cannot read block bitmap - block_group = 136, block_bitmap = 4194312
[517320.051869] EXT4-fs (sda1): Delayed block allocation failed for inode 57934250 at logical offset 67584 with max blocks 2048 with error 5
[517320.051872] EXT4-fs (sda1): This should not happen!! Data will be lost

[517320.055235] EXT4-fs error (device sda1): ext4_wait_block_bitmap:503: comm kworker/u8:2: Cannot read block bitmap - block_group = 136, block_bitmap = 4194312
[517320.055244] EXT4-fs (sda1): previous I/O error to superblock detected
[517320.055330] EXT4-fs error (device sda1): ext4_wait_block_bitmap:503: comm kworker/u8:2: Cannot read block bitmap - block_group = 138, block_bitmap = 4194314
[517320.055335] EXT4-fs (sda1): previous I/O error to superblock detected
[517320.055409] EXT4-fs error (device sda1): ext4_wait_block_bitmap:503: comm kworker/u8:2: Cannot read block bitmap - block_group = 139, block_bitmap = 4194315
[517320.055414] EXT4-fs (sda1): previous I/O error to superblock detected
[517320.055487] EXT4-fs error (device sda1): ext4_wait_block_bitmap:503: comm kworker/u8:2: Cannot read block bitmap - block_group = 140, block_bitmap = 4194316
[517320.055492] EXT4-fs (sda1): previous I/O error to superblock detected
[517320.055564] EXT4-fs error (device sda1): ext4_wait_block_bitmap:503: comm kworker/u8:2: Cannot read block bitmap - block_group = 141, block_bitmap = 4194317
[517320.055569] EXT4-fs (sda1): previous I/O error to superblock detected
[517320.055646] EXT4-fs error (device sda1): ext4_wait_block_bitmap:503: comm kworker/u8:2: Cannot read block bitmap - block_group = 142, block_bitmap = 4194318
[517320.055651] EXT4-fs (sda1): previous I/O error to superblock detected
[517320.055724] EXT4-fs error (device sda1): ext4_wait_block_bitmap:503: comm kworker/u8:2: Cannot read block bitmap - block_group = 143, block_bitmap = 4194319
[517320.055729] EXT4-fs (sda1): previous I/O error to superblock detected
[517320.055826] EXT4-fs error (device sda1): ext4_wait_block_bitmap:503: comm kworker/u8:2: Cannot read block bitmap - block_group = 144, block_bitmap = 4718592
[517320.055830] EXT4-fs (sda1): previous I/O error to superblock detected
[517320.055911] EXT4-fs error (device sda1): ext4_wait_block_bitmap:503: comm kworker/u8:2: Cannot read block bitmap - block_group = 146, block_bitmap = 4718594
[517320.067874] EXT4-fs warning (device sda1): ext4_end_bio:314: I/O error -5 writing to inode 57934250 (offset 268435456 size 3117056 starting block 4455417)
[517320.214464] sd 0:0:0:0: [sda] CDB: Read(10) 28 00 00 dd 1e 80 00 01 00 00
[517320.240574] EXT4-fs warning (device sda1): ext4_end_bio:314: I/O error -5 writing to inode 57934250 (offset 271552512 size 4304896 starting block 4455673)
[517320.240987] EXT4-fs warning (device sda1): ext4_end_bio:314: I/O error -5 writing to inode 57934250 (offset 271552512 size 4304896 starting block 4455929)
[517320.241613] EXT4-fs warning (device sda1): ext4_end_bio:314: I/O error -5 writing to inode 57934250 (offset 271552512 size 4304896 starting block 4456185)
[517320.242488] EXT4-fs warning (device sda1): ext4_end_bio:314: I/O error -5 writing to inode 57934250 (offset 271552512 size 4304896 starting block 4456441)
[517320.243341] EXT4-fs warning (device sda1): ext4_end_bio:314: I/O error -5 writing to inode 57934250 (offset 271552512 size 4304896 starting block 4456468)
[517320.243487] EXT4-fs warning (device sda1): ext4_end_bio:314: I/O error -5 writing to inode 57934250 (offset 275857408 size 966656 starting block 4456704)
[517320.244362] EXT4-fs warning (device sda1): ext4_end_bio:314: I/O error -5 writing to inode 57934250 (offset 285216768 size 8388608 starting block 5636608)
[517320.262465] JBD2: Detected IO errors while flushing file data on sda1-8
[517320.262475] Aborting journal on device sda1-8.
[517320.268423] JBD2: Error -5 detected when updating journal superblock for sda1-8.
[517320.274077] JBD2: Detected IO errors while flushing file data on sda1-8
[517320.285769] EXT4-fs error (device sda1): ext4_journal_check_start:56: Detected aborted journal
[517320.470987] sd 0:0:0:0: [sda] Synchronizing SCSI cache
[517320.724571] sd 0:0:0:0: [sda] Synchronize Cache(10) failed: Result: hostbyte=DID_ERROR driverbyte=DRIVER_OK
[517320.828804] usb 1-2.1: new high-speed USB device number 5 using xhci_hcd
[517320.908983] usb 1-2.1: device descriptor read/64, error -71
[517321.117057] usb 1-2.1: device descriptor read/64, error -71
[517321.324902] usb 1-2.1: new high-speed USB device number 6 using xhci_hcd
[517321.405164] usb 1-2.1: device descriptor read/64, error -71
[517321.613240] usb 1-2.1: device descriptor read/64, error -71
[517321.741314] usb 1-2-port1: attempt power cycle
[517322.345362] usb 1-2.1: new high-speed USB device number 7 using xhci_hcd
[517322.345852] usb 1-2.1: Device not responding to setup address.
[517322.553927] usb 1-2.1: Device not responding to setup address.
[517322.761224] usb 1-2.1: device not accepting address 7, error -71
[517322.845540] usb 1-2.1: new high-speed USB device number 8 using xhci_hcd
[517322.846025] usb 1-2.1: Device not responding to setup address.
[517323.054107] usb 1-2.1: Device not responding to setup address.
[517323.261682] usb 1-2.1: device not accepting address 8, error -71
[517323.282645] usb 1-2-port1: unable to enumerate USB device
[518257.083179] EXT4-fs error: 23 callbacks suppressed
[518257.083195] EXT4-fs error (device sda1): ext4_find_entry:1469: inode #57933830: comm smbd: reading directory lblock 0
[518257.090938] EXT4-fs warning: 38 callbacks suppressed
[518257.090942] EXT4-fs warning (device sda1): htree_dirblock_to_tree:962: inode #57933830: lblock 0: comm smbd: error -5 reading directory block
[518266.467447] EXT4-fs error (device sda1): ext4_find_entry:1469: inode #57933825: comm smbd: reading directory lblock 0
[518266.488432] EXT4-fs warning (device sda1): htree_dirblock_to_tree:962: inode #57933825: lblock 0: comm smbd: error -5 reading directory block
[518266.495064] EXT4-fs warning (device sda1): htree_dirblock_to_tree:962: inode #57933825: lblock 0: comm smbd: error -5 reading directory block
[518268.584524] EXT4-fs warning (device sda1): htree_dirblock_to_tree:962: inode #57933830: lblock 0: comm smbd: error -5 reading directory block
[518274.229260] EXT4-fs warning (device sda1): htree_dirblock_to_tree:962: inode #57933830: lblock 0: comm smbd: error -5 reading directory block
[518274.231683] EXT4-fs warning (device sda1): htree_dirblock_to_tree:962: inode #57933830: lblock 0: comm smbd: error -5 reading directory block
[518274.307266] EXT4-fs warning (device sda1): htree_dirblock_to_tree:962: inode #57933830: lblock 0: comm smbd: error -5 reading directory block
[518277.440586] EXT4-fs warning (device sda1): htree_dirblock_to_tree:962: inode #57933830: lblock 0: comm smbd: error -5 reading directory block
[518281.986029] EXT4-fs warning (device sda1): htree_dirblock_to_tree:962: inode #57933830: lblock 0: comm smbd: error -5 reading directory block
[518285.182387] EXT4-fs warning (device sda1): htree_dirblock_to_tree:962: inode #57933830: lblock 0: comm smbd: error -5 reading directory block
[518285.184334] EXT4-fs warning (device sda1): htree_dirblock_to_tree:962: inode #57933830: lblock 0: comm smbd: error -5 reading directory block
[518507.100126] usb 1-2.1: new high-speed USB device number 9 using xhci_hcd
[518507.210887] usb 1-2.1: New USB device found, idVendor=152d, idProduct=9561
[518507.210904] usb 1-2.1: New USB device strings: Mfr=1, Product=2, SerialNumber=5
[518507.210915] usb 1-2.1: Product: JMS56x Series
[518507.210925] usb 1-2.1: Manufacturer: JMicron
[518507.210935] usb 1-2.1: SerialNumber: 00000000000000000000
[518507.225466] scsi host1: uas
[518507.229954] scsi 1:0:0:0: Direct-Access     WDC WD10 EFRX-68FYTN0     0105 PQ: 0 ANSI: 6
[518507.269407] sd 1:0:0:0: Attached scsi generic sg0 type 0
[518507.269989] sd 1:0:0:0: [sdb] 1953525168 512-byte logical blocks: (1.00 TB/932 GiB)
[518507.272176] sd 1:0:0:0: [sdb] Write Protect is off
[518507.272196] sd 1:0:0:0: [sdb] Mode Sense: 67 00 10 08
[518507.273050] sd 1:0:0:0: [sdb] Write cache: enabled, read cache: enabled, supports DPO and FUA
[518507.329711]  sdb: sdb1
[518507.335963] sd 1:0:0:0: [sdb] Attached SCSI disk

After reading the output above I'm not sure if the problem is:

  • in the disk
  • in the USB disk adapter
  • in the USB controller of the embedded PC
  • in the operating system configuration
  • in the OpenMediaVault configuration

UPDATE

I can exclude the first two options because I connected the adapter to a desktop PC (running Debian) and I tried to do the same operations: it worked flawlessly.

  • The problem is that the USB protocol was not design to sustain constant high speeds and multiple accesses, it is more appropriate for busts, single access – Rui F Ribeiro Mar 13 at 8:46
  • I use daily a lot of USB drives for backups without any problem at all. If the USB wasn't so reliable for this application I don't think we would have such a lot of USB drives out there. – Mark Mar 13 at 8:49

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