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| Thread ID: 111561 | 2010-08-02 06:16:00 | Thank Heavens for RAID | Billy T (70) | Press F1 |
| Post ID | Timestamp | Content | User | ||
| 1123977 | 2010-08-05 09:41:00 | As I read it, when researching RAID for this computer, RAID 0 is striped so unless you use a parity bit, if one disk fails you lose the lot, so this configuration is principally an access-speed enhancer. Just as well you haven't had a disk failure then. RAID 1 is simply mirroring on two disks, while RAID 0+1 has both striping and mirroring to give the best of both worlds, but requires 4 disks to implement, so that was out of the question for me as it would have required 8 disks to keep OS/Progs and Data separate, and the RAID 2 to RAID 6 options were outright overkill. I can't see how you could lose data on RAID 0+1 unless you had a multiple disk fry-up, and likewise with RAID 5, which is another 4 disk configuration, a single disk failure will not lose data but you have to rebuild promptly as a second failure will see you kumara'd. No doubt an expert will correct me if I'm wrong. :D Cheers Billy 8-{) I've got 4 disks, with RAID0 striped across 4 disks for OS + software, and RAID1+0 for data. My position is that I'm willing to take the risk that losing one disk will cause me to lose my OS, but then again, I have frequent full-image backups (locally and offsite) so I could restore that quickly if I needed to. |
somebody (208) | ||
| 1123978 | 2010-08-05 11:03:00 | For me it is an ongoing concurrent backup during daily work, and if a disk fails between normal backups (which I do to an external drive that can be taken off site) not only do I not lose data, but provided I back up every few minutes to the external drive, I can just keep on working with minimal risk. I don't think many PF1 members would have 'off-site backup' facilities, and in fact I doubt that many small to medium sized businesses would either. There is no other system that can keep on recording data input beyond the point of failure of a hard drive and as a one person business, I do not have the luxury of IT support. However, it was my OS/Program drive that failed and that would normally have seen me starting the laborious process of intalling and configuring all my programs again (if I hadn't imaged it). Instead I am back to normal and everything is as it was, all for the mighty initial cost of around $440 for four 640GB disks. For me, that's a no-brainer! Cheers Billy 8-{) I think its time you seriously look at something like carbonite for proper off site back up www.carbonite.com.au |
plod (107) | ||
| 1123979 | 2010-08-05 23:54:00 | Personally I don't think the word 'backup' should be used in connection with RAID . As Nomad said above, RAID is not a backup if you delete an important file or get an intractable infection . So when the first disk failed, the data stored on the second disk wasn't a back-up? Gimme a break! That's a semantic argument at best, but plain old-fashioned pettifogging in my view . I think you are missing the point . There are limits to how far a small business can go in IT expenditure . Raid protects against a single disk failure (or in this case two disks, data and OS), but if I not taken advantage of that facility, had it been the data disk I could have lost all work and emails since my last back up, and that was already stored on an external drive . Realistically I don't think anybody runs an 'instant backup' system so that no data is lost at all, therefore RAID-1 is excellent low-cost insurance between backups . Sure a major lightning strike or other electrical catastrophe could kill both sets of drives simultaneously, but what's the chances of that? Even if it did happen, I only lose work since the last backup, and on critical reports I actually print drafts at each key stage because I find them easier to proof and edit on paper (call me old-fashioned) so I can easily re-enter the work rather than recreating it . Off-site storage is no safer either, data centres have blown up or burned down, financial issues have closed some without warning, and I don't think I'll ever entrust my future to cloud storage, at least not until I have wings and a harp . Cheers Billy 8-{) |
Billy T (70) | ||
| 1123980 | 2010-08-06 00:01:00 | Actually, I run shadow copies on my file server, which is a form of Backup..runs at 10, 12 and 2 each day... Saves me getting the backup tapes out and usually have a file back in about 5 seconds..haha! |
SolMiester (139) | ||
| 1123981 | 2010-08-06 01:31:00 | The point of a backup is meant to provide protection against as many data loss scenarios as possible . In a mirrored RAID array the level of backup protection it provides is low, all you protect against is single (or multiple) drive failure depending on your amount of drives that are mirrored . In the event of a fire, theft, catastrophic PSU failure, lightning stike, flood, etc you lose both drives, and your 'backup' is useless . Even an external hard drive in another room provides protection against a lot more things than just RAID . Of course your methods as you describe above are very sensible, and RAID mirroring plays an important role, but it is more a role of high availability than a backup . |
Agent_24 (57) | ||
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