Case:The customer’s maintenance of the computer is a blue screen. It is a blue screen when it is turned on to skip the BIOS detection item. The hard disk is normal. After entering the PE, the hot -hanging hard disk is also blue screen. Solution:After getting me here, I hung PC3K normally without errors, and…
Case:The operating system is Windows, the file system is NTFS/FAT, using 2T Seagate hard disk.The hard disk emits a click sound. The computer appears blue screen. After detection, the magnetic head is damaged. Solution:The engineer evaluates the degree of damage to the mobile hard disk.According to the requirements of the magnetic head, select the appropriate…
Case:When the customer backup the data, he accidentally touched the backup hard disk to the ground, and then connected the computer to find that the computer speed was dragged very slowly.The customer immediately searched the information through the Internet and found that it should be a hard disk and hardware.The customer’s hard disk is an…
Where’s the best place to keep your data? Online backup services will keep your data safe no matter what sort of disaster strikes your local computers. Online backup services work much like regular backup software. With an online backup service, however, your important data is transmitted over the Internet and securely stored on a server in a professional data center instead of being stored on your own CDs, DVDs, or backup tapes. Most of us still waste time doing this manually which means we often don’t have a backup of our most recent work.
Ten of the top choices for online backup service are:
1. Mozy
Mozy offers reasonably priced unlimited online backup that’s highly configurable, but it could stand some usability improvements.
2. Carbonite
Carbonite tries to make remote backup simple and affordable. Setting it up is a breeze, and restoring a file here or there is also a snap. But restoring a lot of data to a different PC presented some obstacles.
3. SOS Online Backup
This is another backup service that offers a lot of additional features for those users who want to do a lot with the service. It tends to be more user-friendly than IDrive according to most people, though, so you may find that it’s the better of the two choices if you’re just starting out and aren’t quite confident in your own tech-savvy skills. It’s received numerous awards so it’s certainly a good choice.
4. IDrive
There are several reasons that you might enjoy this backup service. It’s got some storage offered entirely for free so it’s great if you’re just starting to figure out whether online backup is even for you or not. It’s also got a lot of great additional features (like advanced search functions and drag-and-drop restoration) that can be used by people who do already like online backup and who want to be able to do more with it.
5. HP Upline
This easy-to-use, reasonably priced online backup service also lets you do local media backups and file sharing, but it lacks important features, like version saving, open-file backup, and the ability to resume interrupted file uploads
The type of online backup service that you want to get is really going to depend a lot on what you need it for. If you’re storing a lot of media then you want a service with a lot of storage. If you’re storing documents that you share with others then you want a backup service that has collaboration features. These five choices are a good place to start in your search for online backup options.
Case:Customers monitoring the video machine hard disk. At that time, the video was mistakenly thought, and the hard disk was formatted, and then recording the video again for two days.The data of the day before the format is required. Solution:Data recovery engineer analysis, monitoring the file system and structure of each brand of videos different,…
–profile
–System wide environment and startup script program.
/dev/MAKEDEV
The /dev/MAKEDEV file is a script written by the system administrator that creates local only device files or links such as device files for a non-standard device driver.
/etc/aliases
Where the user’s name is matched to a nickname for e-mail.
/etc/bootptab
The configuration for the BOOTP server daemon.
/etc/crontab
Lists commands and times to run them for the cron deamon.
/etc/dhcpd.conf
The configuration file for the DHCP server daemon.
/etc/ethers
File for RARP mapping from hardware addresses to IP addresses. See the man page ethers(5).
/etc/exports
The file describing exported filesystems for NFS services.
/etc/fdprm
The floppy disk parameter table. Describes the formats of different floppy disks. Used by setfdprm.
/etc/filesystems
Can be used to set the filesystem probe order when filesystems are mounted with the auto option. The nodev parameter is specified for filesystems that are not really locally mounted systems such as proc, devpts, and nfs systems.
/etc/fstab
Lists the filesystems mounted automatically at startup by the mount -a command (in /etc/rc or equivalent startup file).
/etc/group
Similar to /etc/passwd but for groups rather than users.
/etc/groups
May contain passwords that let a user join a group.
/etc/gshadow
Used to hold the group password and group administrator password information for shadow passwords.
/etc/host.conf
Specifies how host names are resolved.
/etc/hosts
List hosts for name lookup use that are locally required.
/etc/HOSTNAME
Shows the host name of this host. Used for support of older programs since the hostname is stored in the /etc/sysconfig/network file.
/etc/inittab
Configuration file for init, controls startup run levels, determines scripts to start with.
/etc/inetd.conf
Sets up the services that run under the inetd daemon.
/etc/issue
Output by getty before the login prompt. Description or welcoming message.
/etc/issue.net
Output for network logins with LINUX version
/etc/ld.so.conf
Configuration file for ld.so, the run time linker.
/etc/lilo.conf
Configuration file for LILO.
/etc/limits
Limits users resources when a system has shadow passwords installed.
/etc/localtime
In Debian the system time zone is determined by this link.
/etc/login.defs
Sets user login features on systems with shadow passwords.
/etc/logrotate.conf
Configures the logrotate program used for managing logfiles.
/etc/magic
The configuration file for file types. Contains the descriptions of various file formats for the file command.
/etc/motd
The message of the day, automatically output by a successful login.
/etc/mtab
A list of currently mounted file systems. Setup by boot scripts and updated by the mount command.
/etc/named.conf
Used for domain name servers.
/etc/networks
Lists names and addresses of your own and other networks, used by the route command.
/etc/nologin
If this file exists, non-root logins are disabled. Typically it is created when the system is shutting down.
/etc/nsswitch.conf
Name service switch configuration file.
/etc/passwd
The user database with fields giving the username, real name, home directory, encrypted password and other information about each user.
/etc/printcap
A configuration file for printers.
/etc/profile, /etc/cshlogin,/etc/csh/cshrc
Files executed at login or startup time by the Bourne or C shells. These allow the system administrator to set global defaults for all users.
/etc/protocols
Describes DARPA internet protocols available from the TCP/IP subsystem. Maps protocol ID numbers to protocol names.
/etc/rc or /etc/rc.d or /etc/rc?.d
Scripts or directories of scripts to run at startup or when changing run level.
/etc/rc.d/rc0.d
Contains files used to control run level 0. Usually these files are softlink files.
/etc/rc.d/rc1.d
Contains files to control run level 1. Scripts beginning with an S are for start, K for kill.
/etc/rc.d/rc.sysinit
Init runs this when it starts.
/etc/resolv.conf
Configures the name resolver, specifying the address of your name server and your domain name.
/etc/securetty
Identifies secure terminals from which root is allowed to log in.
/etc/services
Lists the network services that the system supports.
/etc/shadow
Shadow password file on systems with shadow password software installed. Shadow passwords move the encrypted password files from /etc/passwd to /etc/shadow which can only be read by root.
/etc/shadow.group
Systems with shadow passwords may have this file.
/etc/shells
Lists trusted shells. The chsh command allows users to change their login shell to shells listed only in this file.
/etc/skel/.profile
Can be used by administrator to set the editor environment variable to some editor that is friendly to new users.
/etc/sudoers
A list of users with special privileges along with the commands they can execute.
/etc/smb.conf
The configuration file for setting up Samba services.
/etc/sysconfig/amd
Used to configure the auto mount daemon.
/etc/sysconfig/clock
Used to configure the system clock to Universal or local time and set some other clock parameters.
/etc/sysconfig/i18n
Controls the system font settings.
/etc/sysconfig/init
This file is used to set some terminal characteristics and environment variables.
/etc/sysconfig/keyboard
Used to configure the keyboard.
/etc/sysconfig/mouse
This file is used to configure the mouse.
/etc/sysconfig/network-scripts/ifcfg-interface
Defines a network interface.
/etc/sysconfig/pcmcia
Used to configure pcmcia network cards.
/etc/sysconfig//routed
Sets up dynamic routing policies.
/etc/sysconfig/static-routes
Configures static routes on a network.
/etc/sysconfig/tape
Used for backup tape device configuration.
/etc/X11/XF86Config
The configuration file for the X server.
/etc/syslog.conf
Configuration file for the syslogd daemon.
/etc/termcap
The terminal capability database. Describes by what “escape sequences” various terminals can be controlled. See terminfo, termcap, curs_termcap man pages.
/etc/terminfo
Details for terminal I/O.
/etc/usertty
This file is used to impose special access restrictions on users.
$HOME/.bashrc
User aliases, path modifier, and functions.
$HOME/.bash_profile
Users environment stuff and startup programs.
$HOME/.bash_logout
User actions to be done at logout.
$HOME/.hushlogin
When this file exists in the user’s home directory, it will prevent check for mail, printing of the last login time, and the message of the day when the user logs in.
$HOME/.inputrc
Contains keybindings and other bits.
$HOME/Xrootenv.0
Has networking and environment info.
/proc/cpuinfo
Information about the processor such as its type, make and performance.
/proc/devices
A list of devices configured into the currently running kernel.
/proc/dma
Shows which DMA channels are being used at the moment.
/proc/filesystems
Filesystems that are configured into the kernel. The file used to detect filesystems if the /etc/filesystems does not exist.
/proc/ioports
Shows which I/O ports are in use at the moment.
/proc/interrupts
Shows which interrupts are in use and how many of each there have been.
/proc/kcore
An image of the physical memory of the system.
/proc/kmsg
Messages output by the kernel. These are also routed to syslog.
/proc/ksyms
Symbol table for the kernel.
/proc/loadavg
The load average of the system.
/proc/meminfo
Information about memory usage, both physical and swap.
/proc/modules
Which kernel modules are currently loaded.
/proc/mounts
Contains information on filesystems currently mounted, similar to /etc/mtab
/proc/net
Contains status information about network protocols.
/proc/self
A symbolic link to the process directory of the program that is looking at /proc. When 2 process look at proc, they get different links.
/proc/stat
Various statistics about the system such as the number of page faults since the system was booted.
/proc/uptime
The time the system has been up.
/proc/version
The kernel version.
/tmp/fvwmrca01339
FVWM-M4 defines. Contains networking, Xwindows, other setup info.
/usr/lib/zoneinfo
Time zone datafiles are stored here on the Debian system
/var/log/lastlog
Used by finger to tell when a user was last logged in.
/var/log/wtmp
Binary info on users that have been logged on. The last command uses this info.
/var/run/utmp
Contains information about users currently logged in. Who and w commands use this file.
/var/named/root.hints
Used for domain name server. Placed here optionally, but this is the normal location.
/var/named/*
Files used by domain name server. Placed here optionally, but this is the normal location.
/var/log/btmp
Used to store information about failed logins. This file must be first created to activate it.
/var/log/lastlog
Contains information about the last time a login was done on the system. Works with lastb(1).
/var/log/maillog
The normal system mail log file.
/var/log/messages
The main system message log file.
var/log/secure
System tracking of user logins. Check this file periodically.
/var/spool/mail
Where mailboxes are usually stored.
Case:The failure description of the Internet cafe Vientiane Silver System to check the database of the database was recovered. After inspection, it was found that the SQL2000 enterprise manager displayed the database of “suspicion”” Solution:Repair the database engineer to repair the MDF database file.(The operation of a large amount of data difficult cases
HDD Printed circuit board (PCB) with board number 100406937 is usually used on these Seagate hard disk drives: ST3500830AS, 9QG, TK, PN 9BJ136-150, FW 3.AAD, Seagate 500GB SATA 3.5 Hard Drive; ST3500830AS, 9QG, TK, PN 9BJ136-276, FW 3.AAE, Seagate 500GB SATA 3.5 Hard Drive; ST3320820AS, 9QF, TK, PN 9BJ13G-305, FW 3.AAE, Seagate 320GB SATA 3.5…
For all answers i found about this topic, the solution was to create, in a certain computer A where i need to install the package, a file containing all dependencies it needs and then downloading it in another computer, let’s call it B. The thing is, i want to have a storage of certain critical…
Striped set with dual distributed parity. Provides fault tolerance from two drive failures; array continues to operate with up to two failed drives. This makes larger RAID groups more practical, especially for high availability systems. This becomes increasingly important because large capacity drives lengthen the time needed to recover from the failure of a single drive. Single parity RAID levels are vulnerable to data loss until the failed drive is rebuilt: the larger the drive, the longer the rebuild will take. Dual parity gives time to rebuild the array without the data being at risk if a (single) additional drive fails before the rebuild is complete.
Advantages
Disadvantages
Recommended Applications
RAID 6 VS RAID 5
RAID 6
In complex arrays (12-24 drives), RAID 6 applications would be a preferred choice due to the fact that Serial ATA drives used in the arrays have a lower duty cycle and may be more likely to fail in 24/7 or business-critical applications.
Raid 5
In small arrays (4-12 drives), RAID 5 applications can quickly repair a failed drive and restore lost data-without taking down the array. It’s perhaps the most cost-effective, fault-tolerant data protection solution currently available for small storage devices.
Pro
Raid 6
Designed for tolerating two simultaneous HDD failures by storing two sets of distributed parities.
Raid 5
Con
Raid 6
Raid 5
Recommended Configuration
Raid 6
Disk array consists of 12 disks or more
Raid 5
Disk array consists of 10 disks or less
Recommended Solutions
Raid 6
Raid 5
