bombproof or overkill recovery plan
If I was starting from scratch... As a method of complete disaster recovery, would it be overkill to buy two identical (cheapish) servers. Server 1 would have two identical 40gb ide disks. I plan to 'dd' from one disk to another each night. Then I'd have a complete image nightly of our server, right? If things went horribly wrong, I could replace server 2's hard drive with either of the two in server 1 and it would work as the hardware in both servers is the same? Is two servers, and two hard drives in server 1, overkill? Or in a school with 600 pupils and staff relying on these systems, is this redundancy sensible, if not necessary? (I'd probably use server 2 to do a copy of any key files and home directories from server 1 as well - they'd be in different areas of the building. This would be for a teacher accidently deleting all their work, or the like). Silly question... Can you 'dd' from the drive your using at the time? ie. If I've booted from, and am using hda, can I use it as my 'dd' input? Thanks for any pointers. -- Matt ________________________________________________________________________ Want to chat instantly with your online friends? Get the FREE Yahoo! Messenger http://uk.messenger.yahoo.com/
--- Matt Johnson
If I was starting from scratch...
:) Is this some bizzare kind of atonement, or attrition?
As a method of complete disaster recovery, would it be overkill to buy two identical (cheapish) servers. Server 1 would have two identical 40gb ide disks. I plan to 'dd' from one disk to another each night. Then I'd have a complete image nightly of our server, right?
Umm, not really. The use of "dd" is complete overkill. That is literally scraping the disk heads for data :) A much easier use is "rsync". It is still the best tool for copying drives or large information across en masse.
If things went horribly wrong, I could replace server 2's hard drive with either of the two in server 1 and it would work as the hardware in both servers is the same?
Yes....you'd have to make sure that the drives went in on the exact same IDE channels too, otherwise your "/dev/hdx"'s will be foobared.
Is two servers, and two hard drives in server 1, overkill? Or in a school with 600 pupils and staff relying on these systems, is this redundancy sensible, if not necessary?
It depends. I used to find when working with the sysadmin at school that backing up 600+ users into tape was effective.
(I'd probably use server 2 to do a copy of any key files and home directories from server 1 as well - they'd be in different areas of the building. This would be for a teacher accidently deleting all their work, or the like).
These "key files" as you call them <wink> are important yes. I mean, what you could do instead is use some kind of backup script and then have the file FTP'ed (or "scp"'ed) to the second server via a cron-job each night.
Silly question... Can you 'dd' from the drive your using at the time? ie. If I've booted from, and am using hda, can I use it as my 'dd' input?
You can yes, but it is not a good idea. As I have said "rsync" is the way to look :) If you want any more help, let me know. Kind Regards, Thomas Adam ===== Thomas Adam "The Linux Weekend Mechanic" -- www.linuxgazette.com ________________________________________________________________________ Want to chat instantly with your online friends? Get the FREE Yahoo! Messenger http://uk.messenger.yahoo.com/
If I was starting from scratch...
The basic plan of having the two servers sounds fine, although (and you may have planned for this already) you will still need some form of removable backup. If the place burns down, two melted servers aren't a lot better than one [g]. Personally, I use DAT drives with afio for backup, All the best, Nial.
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