Isso não tem nada a ver com o Debian, o problema que você está enfrentando acontece muito antes de o sistema operacional ser iniciado. O que é estranho é que isso só acontece às vezes.
Uma possibilidade é que você tenha um disco rígido com falha. Verifique a saída de
sudo smartctl -a /dev/sda
Você deve ver uma linha como esta:
SMART overall-health self-assessment test result: PASSED
Se o seu GRUB não estiver instalado em /dev/sda , substitua /dev/sda pelo dispositivo correto. Você pode precisar instalar o smartctl :
sudo apt-get install smartmontools
UPDATE
A saída que você postou contém estas linhas:
ATA Error Count: 1652 (device log contains only the most recent five errors)
[...]
Error 1652 occurred at disk power-on lifetime: 5265 hours (219 days + 9 hours)
When the command that caused the error occurred, the device was active or idle.
After command completion occurred, registers were:
ER ST SC SN CL CH DH
-- -- -- -- -- -- --
40 51 00 2d 51 60 e0 Error: UNC at LBA = 0x0060512d = 6312237
Commands leading to the command that caused the error were:
CR FR SC SN CL CH DH DC Powered_Up_Time Command/Feature_Name
-- -- -- -- -- -- -- -- ---------------- --------------------
c8 00 01 2d 51 60 00 00 00:16:03.660 READ DMA
27 00 00 00 00 00 00 00 00:16:03.660 READ NATIVE MAX ADDRESS EXT
ec 00 00 00 00 00 00 00 00:16:03.651 IDENTIFY DEVICE
ef 03 46 00 00 00 00 00 00:16:03.644 SET FEATURES [Set transfer mode]
27 00 00 00 00 00 00 00 00:16:03.643 READ NATIVE MAX ADDRESS EXT
Error 1651 occurred at disk power-on lifetime: 5265 hours (219 days + 9 hours)
When the command that caused the error occurred, the device was active or idle.
After command completion occurred, registers were:
ER ST SC SN CL CH DH
-- -- -- -- -- -- --
40 51 00 2d 51 60 e0 Error: UNC at LBA = 0x0060512d = 6312237
Commands leading to the command that caused the error were:
CR FR SC SN CL CH DH DC Powered_Up_Time Command/Feature_Name
-- -- -- -- -- -- -- -- ---------------- --------------------
c8 00 01 2d 51 60 00 00 00:16:01.486 READ DMA
27 00 00 00 00 00 00 00 00:16:01.486 READ NATIVE MAX ADDRESS EXT
ec 00 00 00 00 00 00 00 00:16:01.477 IDENTIFY DEVICE
ef 03 46 00 00 00 00 00 00:16:01.470 SET FEATURES [Set transfer mode]
27 00 00 00 00 00 00 00 00:16:01.470 READ NATIVE MAX ADDRESS EXT
Error 1650 occurred at disk power-on lifetime: 5265 hours (219 days + 9 hours)
When the command that caused the error occurred, the device was active or idle.
After command completion occurred, registers were:
ER ST SC SN CL CH DH
-- -- -- -- -- -- --
40 51 00 2d 51 60 e0 Error: UNC at LBA = 0x0060512d = 6312237
Commands leading to the command that caused the error were:
CR FR SC SN CL CH DH DC Powered_Up_Time Command/Feature_Name
-- -- -- -- -- -- -- -- ---------------- --------------------
c8 00 01 2d 51 60 00 00 00:15:59.544 READ DMA
27 00 00 00 00 00 00 00 00:15:59.544 READ NATIVE MAX ADDRESS EXT
ec 00 00 00 00 00 00 00 00:15:59.535 IDENTIFY DEVICE
ef 03 46 00 00 00 00 00 00:15:59.528 SET FEATURES [Set transfer mode]
27 00 00 00 00 00 00 00 00:15:59.528 READ NATIVE MAX ADDRESS EXT
Error 1649 occurred at disk power-on lifetime: 5265 hours (219 days + 9 hours)
When the command that caused the error occurred, the device was active or idle.
After command completion occurred, registers were:
ER ST SC SN CL CH DH
-- -- -- -- -- -- --
40 51 00 2d 51 60 e0 Error: UNC at LBA = 0x0060512d = 6312237
Commands leading to the command that caused the error were:
CR FR SC SN CL CH DH DC Powered_Up_Time Command/Feature_Name
-- -- -- -- -- -- -- -- ---------------- --------------------
c8 00 01 2d 51 60 00 00 00:15:57.486 READ DMA
27 00 00 00 00 00 00 00 00:15:57.486 READ NATIVE MAX ADDRESS EXT
ec 00 00 00 00 00 00 00 00:15:57.478 IDENTIFY DEVICE
ef 03 46 00 00 00 00 00 00:15:57.478 SET FEATURES [Set transfer mode]
27 00 00 00 00 00 00 00 00:15:57.478 READ NATIVE MAX ADDRESS EXT
Error 1648 occurred at disk power-on lifetime: 5265 hours (219 days + 9 hours)
When the command that caused the error occurred, the device was active or idle.
Então, parece que você tem problemas para ler a partir da unidade. Se isso começou recentemente, sua unidade provavelmente foi danificada. Eu recomendo que você faça um backup rapidamente e compre uma nova unidade .
Antes de trocar as unidades, verifique se os cabos estão conectados corretamente (os cabos da unidade de disco rígido) e tente usar um cabo diferente por precaução.