Case:Use two Seagate 500G hard disks to form an LVM, and use it on the Linux server. After a shutdown and maintenance server, the server cannot restart the problem. Solution:After the engineer got the hard disk, the hard disk was detected and found that one of the hard disks had a large number of bad…
backup policy
an organisation’s procedures and rules for ensuring that adequate amounts and types of backups are made, including suitably frequent testing of the process for restoring the original production system from the backup copies.
backup rotation scheme
a method for effectively backing up data where multiple media are systematically moved from storage to usage in the backup process and back to storage. There are several different schemes. Each takes a different approach to balance the need for a long retention period with frequently backing up changes. Some schemes are more complicated than others.
backup site
a place where business can continue after a data loss event. Such a site may have ready access to the backups or possibly even a continuously updated mirror.
backup software
computer software applications that are used for performing the backing up of data, i.e., the systematic generation of backup copies.
backup window
the period of time that a system is available to perform a backup procedure. Backup procedures can have detrimental effects to system and network performance, sometimes requiring the primary use of the system to be suspended. These effects can be mitigated by arranging a backup window with the users or owners of the system(s).
copy backup
backs up the selected files, but does not mark the files as backed up (reset the archive bit). This is found in the backup with Windows 2003.
cumulative incremental backup
a differential backup used by NetBackup.
daily backup
incremental backup used by Windows Server 2003.
data salvage
the process of recovering data from storage devices when the normal operational methods are impossible. This process is typically performed by specialists in controlled environments with special tools. For example, a crashed hard disk may still have data on it even though it doesn’t work properly. A data salvage specialist might be able to recover much of the original data by opening it up in a clean room and tinkering with the internal parts.
differential backup
a cumulative backup of all changes made since the last full backup. The advantage to this is the quicker recovery time, requiring only a full backup and the latest differential backup to restore the system. The disadvantage is that for each day elapsed since the last full backup, more data needs to be backed up, especially if a majority of the data has been changed.
differential incremental backup
an incremental backup used by NetBackup.
disaster recovery
the process of recovering after a business disaster and restoring or recreating data. One of the main purposes of creating backups is to facilitate a successful disaster recovery. For maximum effectiveness, this process should be planned in advance and audited.
disk image
a method of backing up a whole disk or filesystem in a single image. Since the underlying data structures are what is actually backed up, this method does not allow for file level control over what is selected for backup or restore.
FlashBackup
a term used for raw partition backup used by NetBackup Advanced Client. In NBAC, support is limited to the VxFS (Veritas), ufs (Solaris), Online JFS (HP-UX), and NTFS (Windows) filesystem types. Similar to the UNIX utility dump.
full backup
a backup of all (selected) files on the system. In contrast to a drive image, this does not included the file allocation tables, partition structure and boot sectors.
hot backup
a backup of a database that is still running, and so changes may be made to the data while it is being backed up. Some database engines keep a record of all entries changed, including the complete new value. This can be used to resolve changes made during the backup.
incremental backup
a backup that only contains the files that have changed since the most recent backup (either full or incremental). The advantage of this is quicker backup times, as only changed files need to be saved. The disadvantage is longer recovery times, as the latest full backup, and all incremental backups up to the date of data loss need to be restored.
media spanning
sometimes a backup job is larger than a single destination storage medium. In this case, the job must be broken up into fragments that can be distributed across multiple storage media.
multiplexing
the practice of combining multiple backup data streams into a single stream that can be written to a single storage device. For example, backing up 4 PCs to a single tape drive at once.
multistreaming
the practice of creating multiple backup data streams from a single system to multiple storage devices. For example, backing up a single database to 4 tape drives at once.
normal backup
full backup used by Windows Server 2003.
near store
provisionally backing up data to a local staging backup device, possibly for later archival backup to a remote store device.
open file backup
the ability to back up a file while it is in use by another application. See File locking.
remote store
backing up data to an offsite permanent backup facility, either directly from the live data source or else from an intermediate near store device.
restore time
the amount of time required to bring a desired data set back from the backup media.
retention time
the amount of time in which a given set of data will remain available for restore. Some backup products rely on daily copies of data and measure retention in terms of days. Others retain a number of copies of data changes regardless of the amount of time.
site-to-site backup
backup, over the internet, to an offsite location under the user’s control. Similar to remote backup except that the owner of the data maintains control of the storage location.
synthetic backup
a term used by NetBackup for a restorable backup image that is synthesized on the backup server from a previous full backup and all the incremental backups since then. It is equivalent to what a full backup would be if it were taken at the time of the last incremental backup.
tape library
a storage device which contains tape drives, slots to hold tape cartridges, a barcode reader to identify tape cartridges and an automated method for physically moving tapes within the device. These devices can store immense amounts of data.
true image restore
a term used by NetBackup and Backup Exec for the collection of file deletion and file movement records so that an accurate restore can be performed. For instance, consider a system that has a directory with 5 documents in it on Friday. On Saturday, the system gets a full backup that includes those 5 documents. On Monday, the owner of those documents deletes 2 of them and updates 1 of the 3 remaining. That updated document gets backed up as part of The Monday night incremental backup. On Tuesday afternoon the system crashes. If we perform a normal restore of the full backup from Saturday and the incremental backup from Monday to the fresh system, we will have restored the 2 documents that were intentionally deleted. True image restore keeps track of the deletions with each incremental backup and prevents the deleted files from being inappropriately restored.
trusted paper key
a machine-readable print of a cryptographic key.
virtual Tape Library (VTL)
a storage device that appears to be a tape library to backup software, but actually stores data by some other means. A VTL can be configured as a temporary storage location before data is actually sent to real tapes or it can be the final storage location itself.
I’m using a laptop with TPM module with BitLocker-encrypted internal HDD, running Windows 7.Recently I’ve installed a Windows 8 on the external, eSATA drive.Windows 8 detected the Windows 7 and correctly replaced the bootloader with dual-boot option. Unfortunately, I’m now forced to enter BitLocker Recovery Key each time I start the computer.The only workaround I’ve…
Case:The customer’s computer found that there were abnormal faults, the computer was running slowly, and the sound of abnormal sounds was mixed in use. The customer felt that there was a problem with the problem and immediately turned off to find the network management to check it.The network department technology came to remove the hard…
Case:The hard disk was placed in the pocket, and I didn’t pay attention when I took off my jacket, and fell out of the pocket.Later, I couldn’t recognize it, and there was creaking sound.There are many children’s photos that need to recover mobile hard disk data. Solution:It was tested by our company’s engineer and found…
Case:Seagate 320GB notebook hard disk, customers accidentally broke, and received the detection of our company as a magnetic head damage, abnormal noise, unable to recognize the hard disk, and recovered data. Solution:After the customer’s consent, we first transferred the accessories from the accessories library, and then opened the magnet head in the dust -free room…
TOC
Table of Contents
Track
a radial position of heads over the media (circular ring)
Track following servo (also closed loop)
Control system which reflects if the head is in the correct position over the track, if this isn’t the case, the actuator is instructed to adjust its position (in real time)
Transfer rate
the speed at which the drive sends and receives data from the controller
Thin-film head
an older type head technology, with a single head which reads and writes information (dual function)
TPI
Tracks Per Inch, reflects areal density
UDP (Universal Disk Product)
A file system that supports the current generation of CD’s such as CD-RW, DVD-ROM, DVD-Video
USB (Universal Serial Bus)
A common part on Personal Systems that allow compliant peripherals to be integrated into supporting systems
Voice Coil Motor
electro-magnetic positioning motor (actuator). A wire coil is placed in a stationary magnetic field. When current is passed through the coil the resultant flux causes the coil to move
Winchester Disks
early IBM hard disk model, still used as a reference to today’s HDD
WORM (Write Once Read Many)
description for media which can only be written on once
Case:A HP (HP) website server, the RAID5 array made of 3*500G hard disks with a 3*500G hard disk, found that RAID5 is damaged with a large number of company websites and very important data.I have not done other operations to send to the data recovery company. Solution:Data recovery engineers receive the three SAS hard disks…
When it comes to data storage, viruses can be divided into two basic categories:
Viruses that delete data will tell the operating system (such as Windows) to flag files as being deleted. The data itself becomes unavailable but it still exists on the platters until it’s overwritten. This data is recoverable using Data Recovery Softwares designed to perform data recovery which will scan the platters and mark recognizable files as not deleted, effectively restoring them to the directory structure.
Viruses that corrupt data are the most dangerous because they overwrite files with garbage data and then possibly flag them as deleted. This makes the data unrecoverable.
In either case, it is very important to have antivirus software running on any machine whether it’s connected to the internet or not (viruses can be propagated from CDs, floppies, and other storage mediums) and keep a backup of any critical data on a removable storage device which will help prevent viruses from propagating to your backup.
Case:The important financial form of the customer is placed in the U disk carried by it without leakage, and there are no backups elsewhere. After work today, I need to use the file inside. I found that double -click the U disk.Open the U disk.Because the data is very important, I searched the professional data…
