BACKUP & RESTORE The purpose of backup is to protect data from loss. The purpose of restore is to recover data that is temporarily unavailable due to some unexpected event. SUMBER KEPUSTAKAAN : CHILDRESS/CS5493/.../BACKUP.PPT 1

BACKUP To backup or not to back up, that is the question.  Backup is not free.  No backup is risky. SUMBER KEPUSTAKAAN : CHILDRESS/CS5493/.../BACKUP.PPT 2

FACTORS OF A PROPER BACKUP  Planning  Scheduling  Backup operation  Inventory (content and media)  Verification  Automation  Security SUMBER KEPUSTAKAAN : CHILDRESS/CS5493/.../BACKUP.PPT 3

PLANNING Choose your backup app. Determine which data is critical. Determine frequency and types of backups to be used.  Archival (mirror or image)  Differential  Incremental SUMBER KEPUSTAKAAN : CHILDRESS/CS5493/.../BACKUP.PPT 4

PLANNING Determine which data is static and which is dynamic.  The OS and apps tend to be static; few backups required  E-commerce transactions may require continuous backups.  Understand the changing state of your client’s data to determine an appropriate backup sched.  Organize with partitions SUMBER KEPUSTAKAAN : CHILDRESS/CS5493/.../BACKUP.PPT 5

PLANNING Determine the appropriate media storage for your backups:  CD  DVD  Tape  Disk  Solid State? SUMBER KEPUSTAKAAN : CHILDRESS/CS5493/.../BACKUP.PPT 6

SCHEDULE Full Archival Backup  Mirror backup  image backup Differential Backup Incremental Backup SUMBER KEPUSTAKAAN : CHILDRESS/CS5493/.../BACKUP.PPT 7

FULL ARCHIVAL BACKUP Formatted into a single file and stored on your media choice.  Mirror– every last bit on the disk is duplicated including empty space.  Image - empty space is ignored SUMBER KEPUSTAKAAN : CHILDRESS/CS5493/.../BACKUP.PPT 8

FULL ARCHIVAL BACKUP Provides a complete copy of data Easy to manage:  Done less frequently than other types of backups : Monthly, Quarterly, semi-annually, annually. SUMBER KEPUSTAKAAN : CHILDRESS/CS5493/.../BACKUP.PPT 9

FULL ARCHIVAL BACKUP Consider making multiple backup copies Full backup media should be stored offsite to protect data from:  Fire  Natural disasters (flood, earthquake, etc)  Terrorist attack  Sabotage  Hacker attacks SUMBER KEPUSTAKAAN : CHILDRESS/CS5493/.../BACKUP.PPT 10

DIFFERENTIAL BACKUP Copy the files changed since the last full backup. Differential backups grow with time. They can eventually grow larger than the last full backup. Scheduled less frequently than a full backups: Weekly, monthly. SUMBER KEPUSTAKAAN : CHILDRESS/CS5493/.../BACKUP.PPT 11

DIFFERENTIAL BACKUP (PROS) Redundancy Usually takes up less time and space than a full backup. If the differential backup grows to the size of the last full backup, then schedule a new full backup. SUMBER KEPUSTAKAAN : CHILDRESS/CS5493/.../BACKUP.PPT 12

DIFFERENTIAL BACKUP (CONS) Redundancy – potentially many unneeded copies of the same data (also a potential pro) Subsequent differentials take longer and use more media space. SUMBER KEPUSTAKAAN : CHILDRESS/CS5493/.../BACKUP.PPT 13

INCREMENTAL BACKUPS A backup of what has changed since the last previous backup of any type. Frequency of incremental backups depends on the client needs.  Weekly, daily, hourly, continuously. SUMBER KEPUSTAKAAN : CHILDRESS/CS5493/.../BACKUP.PPT 14

INCREMENTAL BACKUPS Pros  Keeps a revision history of actively changing files  Fastest backup type  Uses the least amount of media Cons  Much more difficult to manage SUMBER KEPUSTAKAAN : CHILDRESS/CS5493/.../BACKUP.PPT 15

BACKUP INVENTORY Inventory the backup media  Tapes and other writable media use barcodes and labels Inventory the content of the media  The backup may require a table of contents SUMBER KEPUSTAKAAN : CHILDRESS/CS5493/.../BACKUP.PPT 16

VERIFY: FIREDRILLS The only time you know the quality of your backup media is when you are doing a restore. This is the worse time to discover you have problems. Pick random files from a backup and restore them. SUMBER KEPUSTAKAAN : CHILDRESS/CS5493/.../BACKUP.PPT 17

FIREDRILLS An occasional test of a full partition restore is not unreasonable. This would be done if  A change is made in the backup software release.  A change of vendor for the backup software product.  When a new server with new unused disk arrives. SUMBER KEPUSTAKAAN : CHILDRESS/CS5493/.../BACKUP.PPT 18

BACKUP AUTOMATION Non automated backups are dangerous. Automation reduces human errors. Choose your app for backup  Carbon Copy Cloner  Macrium Reflect  Tar, cpio, dump, dd SUMBER KEPUSTAKAAN : CHILDRESS/CS5493/.../BACKUP.PPT 19

SECURE: OFF-SITE STORAGE Off site storage has risks all its own  Data can be lost/destroyed in transit  How important is it to have a backup of the backup? SUMBER KEPUSTAKAAN : CHILDRESS/CS5493/.../BACKUP.PPT 20

DATA COMPRESSION Risks – if the media is damaged, recovery may be difficult or impossible. Lossy compression is not suitable for many kinds of data. OK for images, video, or sound. Know your data! No-loss compression for data base files, applications, etc. SUMBER KEPUSTAKAAN : CHILDRESS/CS5493/.../BACKUP.PPT 21

BACKUP COMPRESSION & ENCRYPTION Compression saves space Encryption provides security Lost encryption keys make recovery impossible Some damaged media can be partially recovered. Consider a Mirror Archive (no compression or encryption) SUMBER KEPUSTAKAAN : CHILDRESS/CS5493/.../BACKUP.PPT 22

BACKUP ADDENDUM Backups slow down service.  Files are write-locked during backup. Backups should not be done during peak service hours. Schedule during early AM hours on the weekend. SUMBER KEPUSTAKAAN : CHILDRESS/CS5493/.../BACKUP.PPT 23

RESTORE Three reasons for restores  Accidental file deletion  Disk failure  Disaster recovery  Fire, flood, earthquake, hacker attack, sabotage, terrorist attack, etc. SUMBER KEPUSTAKAAN : CHILDRESS/CS5493/.../BACKUP.PPT 24

ACCIDENTAL FILE DELETION If backups are once per day, lost work is limited to one day for a given file. (RAID does not help) As storage technology gets cheaper by the Gbyte, it becomes easier to implement more sophisticated storage procedures that are more timely. (Mirror backup). A user wants the restoration to be immediate. The quicker the turnaround, the happier your customer. SUMBER KEPUSTAKAAN : CHILDRESS/CS5493/.../BACKUP.PPT 25

TAPES Tape is (or was?) the preferred backup media for very large data storage environments. Tape has a useful life span. Tape can be very robust for storage Easy to tansport Some tape formats are more reliable than others. SUMBER KEPUSTAKAAN : CHILDRESS/CS5493/.../BACKUP.PPT 26

TAPE INVENTORY Backup tapes must be  Properly labeled  Properly stored Proper inventory is needed to do restores in a timely fashion.  Hand written labels are ok  Bar codes and printed labels are better. SUMBER KEPUSTAKAAN : CHILDRESS/CS5493/.../BACKUP.PPT 27

TAPE INVENTORY Inventory is not limited to the physical tape itself. The contents of tapes must be inventoried. The number of accesses must be logged because tapes ware-out. SUMBER KEPUSTAKAAN : CHILDRESS/CS5493/.../BACKUP.PPT 28

TAPE TECHNOLOGY Tape technology expands in leaps. Tape hardware purchases are not made on a constant basis (like disk storage). Tape technology is purchased in leaps. Three year intervals are more practical. SUMBER KEPUSTAKAAN : CHILDRESS/CS5493/.../BACKUP.PPT 29

CENTRALIZATION Costs can be reduced through centralization  Tape mounts are labor intensive, so look to automation. Con  No need for hardware or manpower duplication  Equipment can be interchanged more easily when centralized. SUMBER KEPUSTAKAAN : CHILDRESS/CS5493/.../BACKUP.PPT 30

TECHNOLOGY Disk space cost drops by 1/2 about every months. Disk space is filled as it expands. Disk requirements are increasing on a continuous basis. Disk budgets increase faster than tape backup budgets. SUMBER KEPUSTAKAAN : CHILDRESS/CS5493/.../BACKUP.PPT 31