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