> -----Original Message----- > From: linux-raid-owner@xxxxxxxxxxxxxxx [mailto:linux-raid- > owner@xxxxxxxxxxxxxxx] On Behalf Of Christopher Chen > Sent: Saturday, October 24, 2009 8:51 PM > To: Leslie Rhorer > Cc: berk walker; Mattias Wadenstein; Christian Pernegger; linux- > raid@xxxxxxxxxxxxxxx; adfas asd > Subject: Re: Is My Data DESTROYED?! > > On Sat, Oct 24, 2009 at 6:36 PM, Leslie Rhorer <lrhorer@xxxxxxxxxxx> > wrote: > >> Sir - Whereas Neil, et al, profess that RAID is NOT equal to BACKUP - > >> Most of us know that tape backup is VERY costly, in several ways, in > our > > > > No one used the word "tape". Tapes have not been a practical > means > > of backups for many systems for quite some years. Today, for most large > > systems, the most practical backup solution is hard drive based. Since > the > > OP already has a RAID10 system he has enough or nearly enough drives for > a > > hard drive based backup. Since he is already talking about a remote NAS > > system, his additional costs can be as low as $0, or at most the cost > two or > > three additional drives. > > I think that may be a point of contention. Places where I've worked, > primary data stores, on the order of hundreds of terabytes have been > backed up to tape, and were part of an offsite rotation. Does that True. In the case of many, many terrabytes of data, and if accessibility is not an issue, tapes can be the backup of choice. That's why I said, "for many systems". If the cost of the drive subsystems is in excess of $100K, then spending $40K for a tape drive makes sense, rather than spending another $100K - $20M for a drive based solution. If the total backup is less than 50T in size, or if availability is a concern, then tapes are not a good solution. Right now, at least, tapes cost a bit less than inexpensive disks, but the drive is quite costly. It is only once the cost of the tapoe drive is swamped by the cost of the main drive systems that the tape is more attractive economically. > mean everyone can? Maybe not. But if people can afford to purchase > multi-million dollar SAN and NAS systems, they can certainly afford a > tape library and some LTO tapes. Yeah, but this is a guy with a 4T MythTV server at his house. If he were General Motors searching for a backup solution, I would advise him differently. If he were a storage solutions company, I would advise him differently again. The solution needs to fit the application. > Is it expensive? Certainly. But often > disk-based backups can provide a false sense of economy--disks use > power, take up rack space, generate heat--these are all things people > should consider when building out a data center. This isn't for a data center. For giant systems, these are all a consideration. For systems less than 100T in size, they really aren't. What's more, cold drives don't use any more power than a tape. For medium to large sized off-site backups, removable hard drives are a very attractive solution. At about $60 a terrabyte and less than $500 for the enclosure, it's hard to beat. -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
