tailieunhanh - o reilly Unix Backup and Recovery phần 9

(Xem "Tiện ích sao lưu thương mại" trong Chương 5 giải thích về cách làm việc sao lưu chủ đề.) EBU / RMAN sau đó tất cả các thông tin liên lạc nội bộ mà nó cần phải làm để cung cấp các tiện ích sao lưu với chủ đề n của dữ liệu. Cả hai tiện ích và EBU / RMAN ghi thời gian của các sao lưu để tham khảo trong tương lai | The media is inexpensive and easily available from a number of vendors. Per-disk capacities have grown from 100 MB to GB. The drives themselves are inexpensive. The media retains data longer than many competing formats. M-O drives use the M-O recording method and are readily available from a number of vendors. There is also a big line of automated libraries that support M-O drives and media. This level of automation combined with its low cost make M-O an excellent choice for nearline environments. The format isn t perfect though. Overwriting an M-O cartridge requires multiple passes. However there is a proposed technology called Advanced Storage Magneto-Optical ASMO that promises to solve this problem. ASMO promises a high-speed direct overwrite-rewritable optical system capable of reading both CD-ROM and DVD-ROM disks. It is supposed to have faster transfer rates than any of the DVD technologies a capacity of 6 GB and an infinite number of rewrites. Compare this to DVD-RW s GB and 1 000 rewrites DVD-RAM s GB and 100 000 rewrites and DVD RW s 3 GB and 100 000 rewrites. The reason that the number of rewrites is important is that one of the intended markets is as a permanent secondary storage device for desktop users. If it can achieve a transfer rate of 2 MB s a user could create a full backup of a 6-GB hard drive in under an hour. Making this backup would be as easy as a drag and drop and the resulting disk could be removed to a safe location. The best part though is that the restore is also a simple drag and drop and accessing the file would take seconds not minutes. For More Information This entire optical section could not have been written without the folks at http especially Dana Parker. They were the only available source for a lot of this information. They are keeping close tabs on this highly volatile industry especially the CD and DVD part of it. Make sure you check their web site for updated information. Automated Backup .