Hi, From few weeks, sometimes (4 to 5 times a day) my ubunty gusty system doesnot responds to anything and have to wait a minute or two to use the system normally. I check the log. Below is my output of dmesg What should I do now? Thanks Paras. [ 310.672000] ata1: EH complete [ 317.456000] ata1.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x0 [ 317.456000] ata1.00: (BMDMA stat 0x24) [ 317.456000] ata1.00: cmd c8/00:08:0d:7d:61/00:00:00:00:00/e7 tag 0 cdb 0x0 data 4096 in [ 317.456000] res 51/40:07:0e:7d:61/00:00:00:00:00/e7 Emask 0x9 (media error) [ 317.480000] ata1.00: configured for UDMA/100 [ 317.480000] sd 0:0:0:0: [sda] Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE,SUGGEST_OK [ 317.480000] sd 0:0:0:0: [sda] Sense Key : Medium Error [current] [descriptor] [ 317.480000] Descriptor sense data with sense descriptors (in hex): [ 317.480000] 72 03 11 04 00 00 00 0c 00 0a 80 00 00 00 00 00 [ 317.480000] 07 61 7d 0e [ 317.480000] sd 0:0:0:0: [sda] Add. Sense: Unrecovered read error - auto reallocate failed [ 317.480000] end_request: I/O error, dev sda, sector 123829518 [ 317.480000] ata1: EH complete [ 317.500000] sd 0:0:0:0: [sda] 234441648 512-byte hardware sectors (120034 MB) [ 317.512000] sd 0:0:0:0: [sda] Write Protect is off [ 317.512000] sd 0:0:0:0: [sda] Mode Sense: 00 3a 00 00 [ 317.516000] sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA [ 317.516000] sd 0:0:0:0: [sda] 234441648 512-byte hardware sectors (120034 MB) [ 317.516000] sd 0:0:0:0: [sda] Write Protect is off [ 317.516000] sd 0:0:0:0: [sda] Mode Sense: 00 3a 00 00 [ 317.516000] sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA