并非总是如此，但有时 Ubuntu 需要特别长的时间才能启动和加载桌面环境，即使我使用的是 LTS 发行版。减少启动时间的可能原因和技巧是什么？这里我也添加了我的日志，但我不知道如何理解和利用它来提高速度。
提前谢谢
[ 0.000000] Initializing cgroup subsys cpuset
[ 0.000000] Initializing cgroup subsys cpu
[ 0.000000] Initializing cgroup subsys cpuacct
[ 0.000000] Linux version 3.13.0-74-generic (buildd@lcy01-08) (gcc version 4.8.2 (Ubuntu 4.8.2-19ubuntu1) ) #118-Ubuntu SMP Thu Dec 17 22:52:02 UTC 2015 (Ubuntu 3.13.0-74.118-generic 3.13.11-ckt30)
[ 0.000000] KERNEL supported cpus:
[ 0.000000] Intel GenuineIntel
[ 0.000000] AMD AuthenticAMD
[ 0.000000] NSC Geode by NSC
[ 0.000000] Cyrix CyrixInstead
[ 0.000000] Centaur CentaurHauls
[ 0.000000] Transmeta GenuineTMx86
[ 0.000000] Transmeta TransmetaCPU
[ 0.000000] UMC UMC UMC UMC
[ 0.000000] e820: BIOS-provided physical RAM map:
[ 0.000000] BIOS-e820: [mem 0x0000000000000000-0x000000000009c3ff] usable
[ 0.000000] BIOS-e820: [mem 0x000000000009c400-0x000000000009ffff] reserved
[ 0.000000] BIOS-e820: [mem 0x00000000000dc000-0x00000000000fffff] reserved
[ 0.000000] BIOS-e820: [mem 0x0000000000100000-0x000000007727bfff] usable
[ 0.000000] BIOS-e820: [mem 0x000000007727c000-0x0000000077281fff] reserved
[ 0.000000] BIOS-e820: [mem 0x0000000077282000-0x00000000773edfff] usable
[ 0.000000] BIOS-e820: [mem 0x00000000773ee000-0x000000007740efff] reserved
[ 0.000000] BIOS-e820: [mem 0x000000007740f000-0x000000007746efff] usable
[ 0.000000] BIOS-e820: [mem 0x000000007746f000-0x000000007746ffff] reserved
[ 0.000000] BIOS-e820: [mem 0x0000000077470000-0x00000000774f0fff] ACPI NVS
[ 0.000000] BIOS-e820: [mem 0x00000000774f1000-0x000000007770efff] reserved
[ 0.000000] BIOS-e820: [mem 0x000000007770f000-0x0000000077716fff] usable
[ 0.000000] BIOS-e820: [mem 0x0000000077717000-0x000000007771efff] reserved
[ 0.000000] BIOS-e820: [mem 0x000000007771f000-0x000000007777ffff] usable
[ 0.000000] BIOS-e820: [mem 0x0000000077780000-0x000000007779efff] ACPI NVS
[ 0.000000] BIOS-e820: [mem 0x000000007779f000-0x00000000777e1fff] usable
[ 0.000000] BIOS-e820: [mem 0x00000000777e2000-0x00000000777fefff] ACPI data
[ 0.000000] BIOS-e820: [mem 0x00000000777ff000-0x00000000777fffff] usable
[ 0.000000] BIOS-e820: [mem 0x0000000077800000-0x000000007bffffff] reserved
[ 0.000000] BIOS-e820: [mem 0x00000000f7fff000-0x00000000fbffffff] reserved
[ 0.000000] BIOS-e820: [mem 0x00000000fc804000-0x00000000fc804fff] reserved
[ 0.000000] BIOS-e820: [mem 0x00000000fec00000-0x00000000fec0ffff] reserved
[ 0.000000] BIOS-e820: [mem 0x00000000fed00000-0x00000000fed003ff] reserved
[ 0.000000] BIOS-e820: [mem 0x00000000fed1c000-0x00000000fed8ffff] reserved
[ 0.000000] BIOS-e820: [mem 0x00000000fee00000-0x00000000fee00fff] reserved
[ 0.000000] BIOS-e820: [mem 0x00000000ff000000-0x00000000ffffffff] reserved
[ 0.000000] NX (Execute Disable) protection: active
[ 0.000000] SMBIOS 2.6 present.
[ 0.000000] DMI: SAMSUNG ELECTRONICS CO., LTD. RV411/RV511/E3511/S3511/RV711/E3411/RV411/RV511/E3511/S3511/RV711/E3411, BIOS 04PA.M006.20110615.
[ 0.000000] e820: update [mem 0x00000000-0x00000fff] usable ==> reserved
[ 0.000000] e820: remove [mem 0x000a0000-0x000fffff] usable
[ 0.000000] e820: last_pfn = 0x77800 max_arch_pfn = 0x1000000
[ 0.000000] MTRR default type: uncachable
[ 0.000000] MTRR fixed ranges enabled:
[ 0.000000] 00000-9FFFF write-back
[ 0.000000] A0000-BFFFF uncachable
[ 0.000000] C0000-CFFFF write-protect
[ 0.000000] D0000-FFFFF write-through
[ 0.000000] MTRR variable ranges enabled:
[ 0.000000] 0 disabled
[ 0.000000] 1 base 078000000 mask FF8000000 uncachable
[ 0.000000] 2 base 000000000 mask F80000000 write-back
[ 0.000000] 3 disabled
[ 0.000000] 4 disabled
[ 0.000000] 5 disabled
[ 0.000000] 6 disabled
[ 0.000000] 7 disabled
[ 0.000000] x86 PAT enabled: cpu 0, old 0x7040600070406, new 0x7010600070106
[ 0.000000] original variable MTRRs
[ 0.000000] reg 1, base: 1920MB, range: 128MB, type UC
[ 0.000000] reg 2, base: 0GB, range: 2GB, type WB
[ 0.000000] total RAM covered: 1920M
[ 0.000000] Found optimal setting for mtrr clean up
[ 0.000000] gran_size: 64K chunk_size: 256M num_reg: 2 lose cover RAM: 0G
[ 0.000000] New variable MTRRs
[ 0.000000] reg 0, base: 0GB, range: 2GB, type WB
[ 0.000000] reg 1, base: 1920MB, range: 128MB, type UC
[ 0.000000] found SMP MP-table at [mem 0x000f6660-0x000f666f] mapped at [c00f6660]
[ 0.000000] Scanning 1 areas for low memory corruption
[ 0.000000] initial memory mapped: [mem 0x00000000-0x01ffffff]
[ 0.000000] Base memory trampoline at [c0098000] 98000 size 16384
[ 0.000000] init_memory_mapping: [mem 0x00000000-0x000fffff]
[ 0.000000] [mem 0x00000000-0x000fffff] page 4k
[ 0.000000] init_memory_mapping: [mem 0x37800000-0x379fffff]
[ 0.000000] [mem 0x37800000-0x379fffff] page 2M
[ 0.000000] init_memory_mapping: [mem 0x34000000-0x377fffff]
[ 0.000000] [mem 0x34000000-0x377fffff] page 2M
[ 0.000000] init_memory_mapping: [mem 0x00100000-0x33ffffff]
[ 0.000000] [mem 0x00100000-0x001fffff] page 4k
[ 0.000000] [mem 0x00200000-0x33ffffff] page 2M
[ 0.000000] init_memory_mapping: [mem 0x37a00000-0x37bfdfff]
[ 0.000000] [mem 0x37a00000-0x37bfdfff] page 4k
[ 0.000000] BRK [0x01b9d000, 0x01b9dfff] PGTABLE
[ 0.000000] RAMDISK: [mem 0x35c1e000-0x36e06fff]
[ 0.000000] ACPI: RSDP 000f65a0 000024 (v02 PTLTD )
[ 0.000000] ACPI: XSDT 777f4296 00005C (v01 SECCSD LH43STAR 06040000 LTP 00000000)
[ 0.000000] ACPI: FACP 777e4000 0000F4 (v03 INTEL CALPELLA 06040000 PTEC 00000001)
[ 0.000000] ACPI: DSDT 777e5000 00A8F4 (v02 Intel CALPELLA 06040000 INTL 20060912)
[ 0.000000] ACPI: FACS 7779bfc0 000040
[ 0.000000] ACPI: HPET 777fed86 000038 (v01 INTEL CALPELLA 06040000 PTEC 00000001)
[ 0.000000] ACPI: MCFG 777fedbe 00003C (v01 INTEL CALPELLA 06040000 PTEC 00000001)
[ 0.000000] ACPI: SLIC 777fedfa 000176 (v01 SECCSD LH43STAR 06040000 LTP 00000000)
[ 0.000000] ACPI: APIC 777fef70 000068 (v01 PTLTD ? APIC 06040000 LTP 00000000)
[ 0.000000] ACPI: BOOT 777fefd8 000028 (v01 PTLTD $SBFTBL$ 06040000 LTP 00000001)
[ 0.000000] ACPI: SSDT 777e3000 0009F1 (v01 PmRef CpuPm 00003000 INTL 20061109)
[ 0.000000] ACPI: Local APIC address 0xfee00000
[ 0.000000] 1020MB HIGHMEM available.
[ 0.000000] 891MB LOWMEM available.
[ 0.000000] mapped low ram: 0 - 37bfe000
[ 0.000000] low ram: 0 - 37bfe000
[ 0.000000] BRK [0x01b9e000, 0x01b9efff] PGTABLE
[ 0.000000] Zone ranges:
[ 0.000000] DMA [mem 0x00001000-0x00ffffff]
[ 0.000000] Normal [mem 0x01000000-0x37bfdfff]
[ 0.000000] HighMem [mem 0x37bfe000-0x777fffff]
[ 0.000000] Movable zone start for each node
[ 0.000000] Early memory node ranges
[ 0.000000] node 0: [mem 0x00001000-0x0009bfff]
[ 0.000000] node 0: [mem 0x00100000-0x7727bfff]
[ 0.000000] node 0: [mem 0x77282000-0x773edfff]
[ 0.000000] node 0: [mem 0x7740f000-0x7746efff]
[ 0.000000] node 0: [mem 0x7770f000-0x77716fff]
[ 0.000000] node 0: [mem 0x7771f000-0x7777ffff]
[ 0.000000] node 0: [mem 0x7779f000-0x777e1fff]
[ 0.000000] node 0: [mem 0x777ff000-0x777fffff]
[ 0.000000] On node 0 totalpages: 488592
[ 0.000000] free_area_init_node: node 0, pgdat c19a3880, node_mem_map f4d2e020
[ 0.000000] DMA zone: 32 pages used for memmap
[ 0.000000] DMA zone: 0 pages reserved
[ 0.000000] DMA zone: 3995 pages, LIFO batch:0
[ 0.000000] Normal zone: 1752 pages used for memmap
[ 0.000000] Normal zone: 224254 pages, LIFO batch:31
[ 0.000000] HighMem zone: 2041 pages used for memmap
[ 0.000000] HighMem zone: 260343 pages, LIFO batch:31
[ 0.000000] Using APIC driver default
[ 0.000000] ACPI: PM-Timer IO Port: 0x408
[ 0.000000] ACPI: Local APIC address 0xfee00000
[ 0.000000] ACPI: LAPIC (acpi_id[0x00] lapic_id[0x00] enabled)
[ 0.000000] ACPI: LAPIC (acpi_id[0x01] lapic_id[0x04] enabled)
[ 0.000000] ACPI: LAPIC_NMI (acpi_id[0x00] high edge lint[0x1])
[ 0.000000] ACPI: LAPIC_NMI (acpi_id[0x01] high edge lint[0x1])
[ 0.000000] ACPI: IOAPIC (id[0x01] address[0xfec00000] gsi_base[0])
[ 0.000000] IOAPIC[0]: apic_id 1, version 32, address 0xfec00000, GSI 0-23
[ 0.000000] ACPI: INT_SRC_OVR (bus 0 bus_irq 0 global_irq 2 high edge)
[ 0.000000] ACPI: INT_SRC_OVR (bus 0 bus_irq 9 global_irq 9 high level)
[ 0.000000] ACPI: IRQ0 used by override.
[ 0.000000] ACPI: IRQ2 used by override.
[ 0.000000] ACPI: IRQ9 used by override.
[ 0.000000] Using ACPI (MADT) for SMP configuration information
[ 0.000000] ACPI: HPET id: 0x8086a701 base: 0xfed00000
[ 0.000000] smpboot: Allowing 2 CPUs, 0 hotplug CPUs
[ 0.000000] nr_irqs_gsi: 40
[ 0.000000] PM: Registered nosave memory: [mem 0x0009c000-0x0009cfff]
[ 0.000000] PM: Registered nosave memory: [mem 0x0009d000-0x0009ffff]
[ 0.000000] PM: Registered nosave memory: [mem 0x000a0000-0x000dbfff]
[ 0.000000] PM: Registered nosave memory: [mem 0x000dc000-0x000fffff]
[ 0.000000] e820: [mem 0x7c000000-0xf7ffefff] available for PCI devices
[ 0.000000] Booting paravirtualized kernel on bare hardware
[ 0.000000] setup_percpu: NR_CPUS:8 nr_cpumask_bits:8 nr_cpu_ids:2 nr_node_ids:1
[ 0.000000] PERCPU: Embedded 14 pages/cpu @f7bd9000 s35520 r0 d21824 u57344
[ 0.000000] pcpu-alloc: s35520 r0 d21824 u57344 alloc=14*4096
[ 0.000000] pcpu-alloc: [0] 0 [0] 1
[ 0.000000] Built 1 zonelists in Zone order, mobility grouping on. Total pages: 486808
[ 0.000000] Kernel command line: BOOT_IMAGE=/boot/vmlinuz-3.13.0-74-generic root=UUID=4461d5d7-08c2-401a-b871-fb78bb667679 ro quiet splash vt.handoff=7
[ 0.000000] PID hash table entries: 4096 (order: 2, 16384 bytes)
[ 0.000000] Dentry cache hash table entries: 131072 (order: 7, 524288 bytes)
[ 0.000000] Inode-cache hash table entries: 65536 (order: 6, 262144 bytes)
[ 0.000000] Initializing CPU#0
[ 0.000000] allocated 3915768 bytes of page_cgroup
[ 0.000000] please try 'cgroup_disable=memory' option if you don't want memory cgroups
[ 0.000000] SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=2, Nodes=1
[ 0.000000] Hierarchical RCU implementation.
[ 0.000000] RCU dyntick-idle grace-period acceleration is enabled.
[ 0.000000] RCU restricting CPUs from NR_CPUS=8 to nr_cpu_ids=2.
[ 0.000000] NR_IRQS:2304 nr_irqs:512 16
[ 0.000000] CPU 0 irqstacks, hard=f7008000 soft=f700a000
[ 0.000000] Console: colour dummy device 80x25
[ 0.000000] console [tty0] enabled
[ 0.000000] hpet clockevent registered
[ 0.000000] tsc: Fast TSC calibration using PIT
[ 0.004000] tsc: Detected 2128.185 MHz processor
[ 0.000002] Calibrating delay loop (skipped), value calculated using timer frequency.. 4256.37 BogoMIPS (lpj=8512740)
[ 0.000004] pid_max: default: 32768 minimum: 301
[ 0.000035] Security Framework initialized
[ 0.000050] AppArmor: AppArmor initialized
[ 0.000052] Yama: becoming mindful.
[ 0.000104] Mount-cache hash table entries: 2048 (order: 1, 8192 bytes)
[ 0.000106] Mountpoint-cache hash table entries: 2048 (order: 1, 8192 bytes)
[ 0.275062] \_SB_.PCI0:_OSC invalid UUID
[ 0.275063] _OSC request data:1 1f 0
[ 0.275068] acpi PNP0A08:00: _OSC failed (AE_ERROR); disabling ASPM
[ 0.276042] PCI host bridge to bus 0000:00
[ 0.276046] pci_bus 0000:00: root bus resource [bus 00-3e]
[ 0.276048] pci_bus 0000:00: root bus resource [io 0x0000-0x0cf7]
[ 0.276051] pci_bus 0000:00: root bus resource [io 0x0d00-0xffff]
[ 0.276053] pci_bus 0000:00: root bus resource [mem 0x000a0000-0x000bffff]
[ 0.276055] pci_bus 0000:00: root bus resource [mem 0x000d0000-0x000d3fff]
[ 0.276057] pci_bus 0000:00: root bus resource [mem 0x000d4000-0x000d7fff]
[ 0.276059] pci_bus 0000:00: root bus resource [mem 0x000d8000-0x000dbfff]
[ 0.276061] pci_bus 0000:00: root bus resource [mem 0x7c000000-0xfeafffff]
[ 0.276070] pci 0000:00:00.0: [8086:0044] type 00 class 0x060000
[ 0.276091] DMAR: BIOS has allocated no shadow GTT; disabling IOMMU for graphics
[ 0.276190] pci 0000:00:02.0: [8086:0046] type 00 class 0x030000
[ 0.276204] pci 0000:00:02.0: reg 0x10: [mem 0xfc000000-0xfc3fffff 64bit]
[ 0.276212] pci 0000:00:02.0: reg 0x18: [mem 0xe0000000-0xefffffff 64bit pref]
[ 0.276217] pci 0000:00:02.0: reg 0x20: [io 0x1800-0x1807]
[ 0.276365] pci 0000:00:16.0: [8086:3b64] type 00 class 0x078000
[ 0.276397] pci 0000:00:16.0: reg 0x10: [mem 0xfc805800-0xfc80580f 64bit]
[ 0.276502] pci 0000:00:16.0: PME# supported from D0 D3hot D3cold
[ 0.276626] pci 0000:00:1a.0: [8086:3b3c] type 00 class 0x0c0320
[ 0.276653] pci 0000:00:1a.0: reg 0x10: [mem 0xfc806000-0xfc8063ff]
[ 0.276768] pci 0000:00:1a.0: PME# supported from D0 D3hot D3cold
[ 0.276881] pci 0000:00:1b.0: [8086:3b56] type 00 class 0x040300
[ 0.276904] pci 0000:00:1b.0: reg 0x10: [mem 0xfc800000-0xfc803fff 64bit]
[ 0.277008] pci 0000:00:1b.0: PME# supported from D0 D3hot D3cold
[ 0.277084] pci 0000:00:1b.0: System wakeup disabled by ACPI
[ 0.277123] pci 0000:00:1c.0: [8086:3b42] type 01 class 0x060400
[ 0.277229] pci 0000:00:1c.0: PME# supported from D0 D3hot D3cold
[ 0.277306] pci 0000:00:1c.0: System wakeup disabled by ACPI
[ 0.277348] pci 0000:00:1c.3: [8086:3b48] type 01 class 0x060400
[ 0.277454] pci 0000:00:1c.3: PME# supported from D0 D3hot D3cold
[ 0.277531] pci 0000:00:1c.3: System wakeup disabled by ACPI
[ 0.277581] pci 0000:00:1d.0: [8086:3b34] type 00 class 0x0c0320
[ 0.277608] pci 0000:00:1d.0: reg 0x10: [mem 0xfc806400-0xfc8067ff]
[ 0.277722] pci 0000:00:1d.0: PME# supported from D0 D3hot D3cold
[ 0.277828] pci 0000:00:1e.0: [8086:2448] type 01 class 0x060401
[ 0.277965] pci 0000:00:1e.0: System wakeup disabled by ACPI
[ 0.278004] pci 0000:00:1f.0: [8086:3b09] type 00 class 0x060100
[ 0.278217] pci 0000:00:1f.2: [8086:3b29] type 00 class 0x010601
[ 0.278246] pci 0000:00:1f.2: reg 0x10: [io 0x1818-0x181f]
[ 0.278257] pci 0000:00:1f.2: reg 0x14: [io 0x180c-0x180f]
[ 0.278269] pci 0000:00:1f.2: reg 0x18: [io 0x1810-0x1817]
[ 0.278281] pci 0000:00:1f.2: reg 0x1c: [io 0x1808-0x180b]
[ 0.278293] pci 0000:00:1f.2: reg 0x20: [io 0x1820-0x183f]
[ 0.278305] pci 0000:00:1f.2: reg 0x24: [mem 0xfc805000-0xfc8057ff]
[ 0.278376] pci 0000:00:1f.2: PME# supported from D3hot
[ 0.278482] pci 0000:00:1f.3: [8086:3b30] type 00 class 0x0c0500
[ 0.278505] pci 0000:00:1f.3: reg 0x10: [mem 0xfc806800-0xfc8068ff 64bit]
[ 0.278537] pci 0000:00:1f.3: reg 0x20: [io 0x1840-0x185f]
[ 0.278665] pci 0000:00:1f.6: [8086:3b32] type 00 class 0x118000
[ 0.278696] pci 0000:00:1f.6: reg 0x10: [mem 0xfc804000-0xfc804fff 64bit]
[ 0.279018] pci 0000:02:00.0: [14e4:4727] type 00 class 0x028000
[ 0.279052] pci 0000:02:00.0: reg 0x10: [mem 0xfc500000-0xfc503fff 64bit]
[ 0.279217] pci 0000:02:00.0: supports D1 D2
[ 0.279219] pci 0000:02:00.0: PME# supported from D0 D3hot D3cold
[ 0.283719] pci 0000:00:1c.0: PCI bridge to [bus 02-03]
[ 0.283729] pci 0000:00:1c.0: bridge window [io 0x2000-0x2fff]
[ 0.283739] pci 0000:00:1c.0: bridge window [mem 0xfc500000-0xfc5fffff]
[ 0.283753] pci 0000:00:1c.0: bridge window [mem 0xfcc00000-0xfcdfffff 64bit pref]
[ 0.283857] pci 0000:04:00.0: [10ec:8168] type 00 class 0x020000
[ 0.283876] pci 0000:04:00.0: reg 0x10: [io 0x3000-0x30ff]
[ 0.283906] pci 0000:04:00.0: reg 0x18: [mem 0xfc900000-0xfc900fff 64bit pref]
[ 0.283924] pci 0000:04:00.0: reg 0x20: [mem 0xfca04000-0xfca07fff 64bit pref]
[ 0.293577] pci 0000:3f:00.1: [8086:2d01] type 00 class 0x060000
[ 0.293625] pci 0000:3f:02.0: [8086:2d10] type 00 class 0x060000
[ 0.293669] pci 0000:3f:02.1: [8086:2d11] type 00 class 0x060000
[ 0.293712] pci 0000:3f:02.2: [8086:2d12] type 00 class 0x060000
[ 0.293755] pci 0000:3f:02.3: [8086:2d13] type 00 class 0x060000
[ 0.293809] pci_bus 0000:3f: on NUMA node 0
[ 0.294026] ACPI: Enabled 5 GPEs in block 00 to 3F
[ 0.294034] ACPI: \_SB_.PCI0: notify handler is installed
[ 0.294114] ACPI: \_SB_.CPBG: notify handler is installed
[ 0.294123] Found 2 acpi root devices
[ 0.294385] ACPI : EC: GPE = 0x17, I/O: command/status = 0x66, data = 0x62
[ 0.294525] ACPI : EC: 0 stale EC events cleared
[ 0.294657] vgaarb: setting as boot device: PCI:0000:00:02.0
[ 0.294660] vgaarb: device added: PCI:0000:00:02.0,decodes=io+mem,owns=io+mem,locks=none
[ 0.294664] vgaarb: loaded
[ 0.294666] vgaarb: bridge control possible 0000:00:02.0
[ 0.294864] SCSI subsystem initialized
[ 0.294902] libata version 3.00 loaded.
[ 0.294926] ACPI: bus type USB registered
[ 0.294947] usbcore: registered new interface driver usbfs
[ 0.294956] usbcore: registered new interface driver hub
[ 0.294980] usbcore: registered new device driver usb
[ 0.295091] PCI: Using ACPI for IRQ routing
[ 0.297463] PCI: pci_cache_line_size set to 64 bytes
[ 0.297554] e820: reserve RAM buffer [mem 0x0009c400-0x0009ffff]
[ 0.297556] e820: reserve RAM buffer [mem 0x7727c000-0x77ffffff]
[ 0.297560] e820: reserve RAM buffer [mem 0x773ee000-0x77ffffff]
[ 0.297563] e820: reserve RAM buffer [mem 0x7746f000-0x77ffffff]
[ 0.297566] e820: reserve RAM buffer [mem 0x77717000-0x77ffffff]
[ 0.297568] e820: reserve RAM buffer [mem 0x77780000-0x77ffffff]
[ 0.297570] e820: reserve RAM buffer [mem 0x777e2000-0x77ffffff]
[ 0.297572] e820: reserve RAM buffer [mem 0x77800000-0x77ffffff]
[ 0.297665] NetLabel: Initializing
[ 0.297667] NetLabel: domain hash size = 128
[ 0.297668] NetLabel: protocols = UNLABELED CIPSOv4
[ 0.297680] NetLabel: unlabeled traffic allowed by default
[ 0.297794] hpet0: at MMIO 0xfed00000, IRQs 2, 8, 0, 0, 0, 0, 0, 0
[ 0.297800] hpet0: 8 comparators, 64-bit 14.318180 MHz counter
[ 0.299836] Switched to clocksource hpet
[ 0.306629] AppArmor: AppArmor Filesystem Enabled
[ 0.306662] pnp: PnP ACPI init
[ 0.306680] ACPI: bus type PNP registered
[ 0.307041] pnp 00:00: [dma 4]
[ 0.307072] pnp 00:00: Plug and Play ACPI device, IDs PNP0200 (active)
[ 0.307099] pnp 00:01: Plug and Play ACPI device, IDs INT0800 (active)
[ 0.307210] pnp 00:02: Plug and Play ACPI device, IDs PNP0103 (active)
[ 0.307243] pnp 00:03: Plug and Play ACPI device, IDs PNP0c04 (active)
[ 0.307309] system 00:04: [io 0x0680-0x069f] has been reserved
[ 0.307312] system 00:04: [io 0x0500-0x050f] has been reserved
[ 0.307314] system 00:04: [io 0x0600-0x0603] has been reserved
[ 0.307317] system 00:04: [io 0xffff] has been reserved
[ 0.307320] system 00:04: [io 0x0400-0x047f] could not be reserved
[ 0.307322] system 00:04: [io 0x1180-0x11ff] has been reserved
[ 0.307324] system 00:04: [io 0x164e-0x164f] has been reserved
[ 0.307327] system 00:04: [io 0xfe00] has been reserved
[ 0.307330] system 00:04: Plug and Play ACPI device, IDs PNP0c02 (active)
[ 0.307391] system 00:05: [io 0x06a0-0x06af] has been reserved
[ 0.307394] system 00:05: [io 0x06b0-0x06ff] has been reserved
[ 0.307397] system 00:05: Plug and Play ACPI device, IDs PNP0c02 (active)
[ 0.307446] pnp 00:06: Plug and Play ACPI device, IDs PNP0b00 (active)
[ 0.307482] pnp 00:07: Plug and Play ACPI device, IDs PNP0303 (active)
[ 0.307527] pnp 00:08: Plug and Play ACPI device, IDs PNP0f13 (active)
[ 0.307969] system 00:09: [mem 0xfed1c000-0xfed1ffff] has been reserved
[ 0.307972] system 00:09: [mem 0xfed10000-0xfed13fff] has been reserved
[ 0.307975] system 00:09: [mem 0xfed18000-0xfed18fff] has been reserved
[ 0.307977] system 00:09: [mem 0xfed19000-0xfed19fff] has been reserved
[ 0.307980] system 00:09: [mem 0xf8000000-0xfbffffff] has been reserved
[ 0.307982] system 00:09: [mem 0xf7fff000-0xf7ffffff] has been reserved
[ 0.307985] system 00:09: [mem 0xfed20000-0xfed3ffff] has been reserved
[ 0.307987] system 00:09: [mem 0xfed40000-0xfed44fff] has been reserved
[ 0.307990] system 00:09: [mem 0xfed45000-0xfed8ffff] has been reserved
[ 0.307992] system 00:09: [mem 0xff000000-0xffffffff] has been reserved
[ 0.307995] system 00:09: [mem 0xfee00000-0xfeefffff] could not be reserved
[ 0.307998] system 00:09: Plug and Play ACPI device, IDs PNP0c02 (active)
[ 0.308382] pnp: PnP ACPI: found 10 devices
[ 0.308383] ACPI: bus type PNP unregistered
[ 0.308387] PnPBIOS: Disabled by ACPI PNP
[ 0.345282] pci 0000:00:1c.0: PCI bridge to [bus 02-03]
[ 0.345287] pci 0000:00:1c.0: bridge window [io 0x2000-0x2fff]
[ 0.345294] pci 0000:00:1c.0: bridge window [mem 0xfc500000-0xfc5fffff]
[ 0.345300] pci 0000:00:1c.0: bridge window [mem 0xfcc00000-0xfcdfffff 64bit pref]
[ 0.345308] pci 0000:00:1c.3: PCI bridge to [bus 04-05]
[ 0.345312] pci 0000:00:1c.3: bridge window [io 0x3000-0x3fff]
[ 0.345319] pci 0000:00:1c.3: bridge window [mem 0xfc400000-0xfc4fffff]
[ 0.345324] pci 0000:00:1c.3: bridge window [mem 0xfc900000-0xfcbfffff 64bit pref]
[ 0.345332] pci 0000:00:1e.0: PCI bridge to [bus 06]
[ 0.345349] pci_bus 0000:00: resource 4 [io 0x0000-0x0cf7]
[ 0.345351] pci_bus 0000:00: resource 5 [io 0x0d00-0xffff]
[ 0.345353] pci_bus 0000:00: resource 6 [mem 0x000a0000-0x000bffff]
[ 0.345355] pci_bus 0000:00: resource 7 [mem 0x000d0000-0x000d3fff]
[ 0.345357] pci_bus 0000:00: resource 8 [mem 0x000d4000-0x000d7fff]
[ 0.345360] pci_bus 0000:00: resource 9 [mem 0x000d8000-0x000dbfff]
[ 0.345362] pci_bus 0000:00: resource 10 [mem 0x7c000000-0xfeafffff]
[ 0.345364] pci_bus 0000:02: resource 0 [io 0x2000-0x2fff]
[ 0.345366] pci_bus 0000:02: resource 1 [mem 0xfc500000-0xfc5fffff]
[ 0.345368] pci_bus 0000:02: resource 2 [mem 0xfcc00000-0xfcdfffff 64bit pref]
[ 0.345371] pci_bus 0000:04: resource 0 [io 0x3000-0x3fff]
[ 0.345373] pci_bus 0000:04: resource 1 [mem 0xfc400000-0xfc4fffff]
[ 0.345375] pci_bus 0000:04: resource 2 [mem 0xfc900000-0xfcbfffff 64bit pref]
[ 0.345377] pci_bus 0000:06: resource 4 [io 0x0000-0x0cf7]
[ 0.345379] pci_bus 0000:06: resource 5 [io 0x0d00-0xffff]
[ 0.345381] pci_bus 0000:06: resource 6 [mem 0x000a0000-0x000bffff]
[ 0.345383] pci_bus 0000:06: resource 7 [mem 0x000d0000-0x000d3fff]
[ 0.345385] pci_bus 0000:06: resource 8 [mem 0x000d4000-0x000d7fff]
[ 0.345387] pci_bus 0000:06: resource 9 [mem 0x000d8000-0x000dbfff]
[ 0.345390] pci_bus 0000:06: resource 10 [mem 0x7c000000-0xfeafffff]
[ 0.345428] NET: Registered protocol family 2
[ 0.345658] TCP established hash table entries: 8192 (order: 3, 32768 bytes)
[ 0.345674] TCP bind hash table entries: 8192 (order: 4, 65536 bytes)
[ 0.345696] TCP: Hash tables configured (established 8192 bind 8192)
[ 0.345714] TCP: reno registered
[ 0.345717] UDP hash table entries: 512 (order: 2, 16384 bytes)
[ 0.345723] UDP-Lite hash table entries: 512 (order: 2, 16384 bytes)
[ 0.345775] NET: Registered protocol family 1
[ 0.345788] pci 0000:00:02.0: Video device with shadowed ROM
[ 0.346393] PCI: CLS 64 bytes, default 64
[ 0.346447] Trying to unpack rootfs image as initramfs...
[ 0.742234] Freeing initrd memory: 18340K (f5c1e000 - f6e07000)
[ 0.742351] Simple Boot Flag at 0x37 set to 0x1
[ 0.742505] microcode: CPU0 sig=0x20655, pf=0x10, revision=0x2
[ 0.742513] microcode: CPU1 sig=0x20655, pf=0x10, revision=0x2
[ 0.742592] microcode: Microcode Update Driver: v2.00 <[email protected]>, Peter Oruba
[ 0.742595] Scanning for low memory corruption every 60 seconds
[ 0.742837] Initialise system trusted keyring
[ 0.742883] audit: initializing netlink socket (disabled)
[ 0.742896] type=2000 audit(1453567278.624:1): initialized
[ 0.767270] bounce pool size: 64 pages
[ 0.767281] HugeTLB registered 2 MB page size, pre-allocated 0 pages
[ 0.768560] zbud: loaded
[ 0.768640] VFS: Disk quotas dquot_6.5.2
[ 0.768690] Dquot-cache hash table entries: 1024 (order 0, 4096 bytes)
[ 0.769192] fuse init (API version 7.22)
[ 0.769278] msgmni has been set to 1720
[ 0.769344] Key type big_key registered
[ 0.769803] Key type asymmetric registered
[ 0.769806] Asymmetric key parser 'x509' registered
[ 0.769842] Block layer SCSI generic (bsg) driver version 0.4 loaded (major 252)
[ 0.769875] io scheduler noop registered
[ 0.769877] io scheduler deadline registered (default)
[ 0.769907] io scheduler cfq registered
[ 0.770427] pci_hotplug: PCI Hot Plug PCI Core version: 0.5
[ 0.770445] pciehp: PCI Express Hot Plug Controller Driver version: 0.4
[ 0.770489] vesafb: mode is 1024x768x32, linelength=4096, pages=0
[ 0.770491] vesafb: scrolling: redraw
[ 0.770493] vesafb: Truecolor: size=8:8:8:8, shift=24:16:8:0
[ 0.771617] vesafb: framebuffer at 0xe0000000, mapped to 0xf8480000, using 3072k, total 3072k
[ 1.520711] sd 0:0:0:0: [sda] Write Protect is off
[ 1.520718] sd 0:0:0:0: [sda] Mode Sense: 00 3a 00 00
[ 1.520865] sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
[ 21.529215] type=1400 audit(1453567300.192:14): apparmor="STATUS" operation="profile_load" profile="unconfined" name="/opt/extras.ubuntu.com/unity-lens-askubuntu/unity-askubuntu-daemon" pid=792 comm="apparmor_parser"
[ 21.531003] type=1400 audit(1453567300.196:15): apparmor="STATUS" operation="profile_replace" profile="unconfined" name="/sbin/dhclient" pid=793 comm="apparmor_parser"
[ 21.531011] type=1400 audit(1453567300.196:16): apparmor="STATUS" operation="profile_replace" profile="unconfined" name="/usr/lib/NetworkManager/nm-dhcp-client.action" pid=793 comm="apparmor_parser"
[ 21.531017] type=1400 audit(1453567300.196:17): apparmor="STATUS" operation="profile_replace" profile="unconfined" name="/usr/lib/connman/scripts/dhclient-script" pid=793 comm="apparmor_parser"
[ 21.810062] init: samba4 main process (747) terminated with status 1
[ 22.085377] init: Failed to spawn hybrid-gfx main process: unable to execute: No such file or directory
答案1
检查日志：
使用 Upstart 的旧系统
gksudo gedit /var/log/dmesg
sudo grep -E -i "error|warning" /var/log/dmesg
带有 systemd 的较新系统：
systemd-analyze blame
答案2
如果您的安装是加密的，那么由于加密不当，Ubuntu 的运行速度可能会变慢。
如果您的安装未加密，您可以安装 BleachBit 并使用它整理您的机器。
sudo apt-get update
sudo apt-get install bleachbit