tailieunhanh - Unix Backup and Recovery phần 3

Hầu hết các chủ đề này cũng được bao phủ trong tài liệu từ các nhà cung cấp thích hợp, cuốn sách này không có nghĩa là để thay thế cho tài liệu. Tôi cố gắng để giải thích những điều không được đề cập trong tài liệu hướng dẫn và có thể giải quyết một số đối tượng thẳng thắn hơn so với một hướng dẫn sử dụng | normal Unix tools such as mt dd and gunzip uncompress are needed to recover a dump image from tape if AMANDA is not available. When AMANDA software is available it locates which tapes are needed and finds images on the tapes. AMANDA is meant to run unattended such as from a nightly cron job. Client hosts that are down or hung are noted and bypassed. Tape errors cause AMANDA to fall Page 149 back to degraded mode in which backups are still performed but only to the holding disks. They may be flushed to tape by hand after the problem is resolved. AMANDA has configuration options for controlling almost all aspects of the backup operation and provides several scheduling methods. A typical configuration does periodic full dumps with partial dumps in between. There is also support for Periodic archival backup for purposes such as taking full dumps to a vault away from the primary site Incremental-only backups in which full dumps are done outside of AMANDA such as for very active areas that must be taken offline or no full dumps at all for areas that can easily be recovered from vendor media Full dumps such as of database areas that change completely between each run or critical areas that are easier to deal with during an emergency if they are a single-restore operation It s easy to support multiple configurations on the same tape server machine such as a periodic archival configuration along side a normal daily configuration. Multiple configurations can run simultaneously on the same tape server if there are multiple tape drives. Scheduling full dumps is typically left up to AMANDA. They are scattered throughout the dump cycle to balance the amount of data backed up each run. It s important to keep logs of where backup images are each area which AMANDA does for you since they are not on a specific predictable tape . the Friday tape will not always have a full dump of usr for client A . The partial backup level also is left to AMANDA. History information about .