Re: RAID-1 as back-up
On Jun 4, 2005, at 18:41, Karl Denninger wrote: Having an offsite copy is just good common sense. Best to make it an explicit comment. As the saying goes, common sense often isn't (common). :) ___ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: RAID-1 as back-up
On Sat, Jun 04, 2005 at 04:57:52PM -0400, David Magda wrote: > > On Jun 3, 2005, at 18:50, Karl Denninger wrote: > > >As with all backup strategies (absent write-once media in SOME cases) > >if the > >media is PHYSICALLY connected to the machine and it is hacked it is > >possible > >for a hacker to scribble on THAT as well. This is no more likely, > >however, > > Or a voltage spike to fry it (the OP has a UPS, right?). Or if there is > some flooding it will scramble things as well. > > Regardless of media you use, make sure there is at least one back up > off site. I've heard of some insurance companies not paying out the > business continuation payments since there was no off site data (it was > a condition in the agreement / contract). Having an offsite copy is just good common sense. My point is that there are other ways to do this beyond traditional tape media, and that a RAID system is a perfectly-viable means of accomplishing the goal. - -- Karl Denninger ([EMAIL PROTECTED]) Internet Consultant & Kids Rights Activist http://www.denninger.netMy home on the net - links to everything I do! http://scubaforum.org Your UNCENSORED place to talk about DIVING! http://www.spamcuda.net SPAM FREE mailboxes - FREE FOR A LIMITED TIME! http://genesis3.blogspot.comMusings Of A Sentient Mind ___ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: RAID-1 as back-up
On Jun 3, 2005, at 18:50, Karl Denninger wrote: As with all backup strategies (absent write-once media in SOME cases) if the media is PHYSICALLY connected to the machine and it is hacked it is possible for a hacker to scribble on THAT as well. This is no more likely, however, Or a voltage spike to fry it (the OP has a UPS, right?). Or if there is some flooding it will scramble things as well. Regardless of media you use, make sure there is at least one back up off site. I've heard of some insurance companies not paying out the business continuation payments since there was no off site data (it was a condition in the agreement / contract). ___ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: RAID-1 as back-up
On Fri, Jun 03, 2005 at 06:36:34PM -0400, Alec Berryman wrote: > Hans F. Nordhaug on 2005-06-04 00:26:20 +0200: > > > I would like to use RAID-1 as a back-up solution. If one of the disk > > breaks I would like my server to continue to run from the other > > disk. > > Just as fair warning, you should not rely on RAID as a 'backup' like > you would rely on writing to removable media and storing off-site. If > someone cracks your computer and you want to go back to known good > snapshot, you're out of luck; if you accidently overwrite something, > RAID won't help you. That depends. You can use a third volume in a RAID1 system to image to nightly under automatic control and detach it when finished. Done with care this disk will NOT be used at boot (it might actually boot the kernel, BUT it is not considered one of the providers in gmirror if you "remove" it, so it will not come back into the configuration on a restart) If a hacker scribbles on your disks, this one can still be booted manually with a bit of effort (couple of commands from single user mode.) It will not come up clean but if care is taken (e.g. flushing any open DBMS processes that are active at the time of the detach) you can insure that critical areas on the system are intact, even though a FSCK will be required. You can also (since the disk is detached) physically remove it from the machine (assuming hardware support for such a thing) and physically take the disk somewhere and shove it in an offsite location. The beauty of this over a tape backup is that it is MUCH faster (I can copy about 300GB this way in under five hours), is a true image copy and the resulting media is directly bootable (no restore required) It can also be mounted separately if necessary with the system running (if set up correctly) so you can incrementally copy a file that has been removed by accident, for example, back onto the working volumes. Another option is to DUMP to a disk. Using the snapshop features this is even safer in terms of data integrity but you lose the online nature of the backup (it has to be restored if there is a problem; you can't just boot the volume.) It also allows incremental backups if you desire to use them. As with all backup strategies (absent write-once media in SOME cases) if the media is PHYSICALLY connected to the machine and it is hacked it is possible for a hacker to scribble on THAT as well. This is no more likely, however, than it is for a tape cartridge system (e.g. tape library, etc) that is likewise available while the machine is running. Backup up to a disk drive is becoming much more attractive in terms of total cost, especially when one includes in the picture the time required to restore. The high-capacity tape makers are no longer necessarily the option of choice for this necessary function. -- -- Karl Denninger ([EMAIL PROTECTED]) Internet Consultant & Kids Rights Activist http://www.denninger.netMy home on the net - links to everything I do! http://scubaforum.org Your UNCENSORED place to talk about DIVING! http://www.spamcuda.net SPAM FREE mailboxes - FREE FOR A LIMITED TIME! http://genesis3.blogspot.comMusings Of A Sentient Mind ___ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: RAID-1 as back-up
Hans F. Nordhaug on 2005-06-04 00:26:20 +0200: > I would like to use RAID-1 as a back-up solution. If one of the disk > breaks I would like my server to continue to run from the other > disk. Just as fair warning, you should not rely on RAID as a 'backup' like you would rely on writing to removable media and storing off-site. If someone cracks your computer and you want to go back to known good snapshot, you're out of luck; if you accidently overwrite something, RAID won't help you. > I'm running 5.3 - what do you recommend - gvinum, ccd, others? What > is the definitive howto for the recommend solution. You should use gmirror. There's an excellent guide - http://people.freebsd.org/~rse/mirror/. I've been using gmirror for about half a year and have had no problems. pgpxpx0468PZt.pgp Description: PGP signature
Re: RAID-1 as back-up
On Sat, Jun 04, 2005 at 12:26:20AM +0200, Hans F. Nordhaug wrote: > Dear list, > > I would like to use RAID-1 as a back-up solution. If one of the disk > breaks I would like my server to continue to run from the other disk. > I have followed the mailing list for a while and read some howtos, > but I'm not sure if this is possible (without doing all kinds of tricks > when the accidents happens - removing meta data and so on). In > addition, I thought, gvinum was the way to go, but hasn't there been > some problems with it (reported here lately)? I'm running 5.3 - what > do you recommend - gvinum, ccd, others? What is the definitive howto for > the recommend solution. Thx for your time. > > Regards, > Hans I do this using gmirror; I run a two-disk Raid1 system for normal operaton, and back up to a third device which a CRON job attaches and detaches nightly to image the system. The detached disk is removed, so it will not be detected as a valid device on boot. If the online mirror breaks (either disk) the other continues on its merry way. In a catastrophe where the system scribbles on BOTH disks, the other volume can be booted manually and with a bit of effort (couple of command-line entries from single user mode) brought online as a single device. -- -- Karl Denninger ([EMAIL PROTECTED]) Internet Consultant & Kids Rights Activist http://www.denninger.netMy home on the net - links to everything I do! http://scubaforum.org Your UNCENSORED place to talk about DIVING! http://www.spamcuda.net SPAM FREE mailboxes - FREE FOR A LIMITED TIME! http://genesis3.blogspot.comMusings Of A Sentient Mind ___ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "[EMAIL PROTECTED]"
