Date: Sat, 1 Aug 1998 12:56:41 -0700 (PDT) From: Scott <scott@SchematiX.net> To: Nathan Dorfman <nathan@fcc.net> Cc: Andrew Bromage <bromage@queens.unimelb.edu.au>, freebsd-stable@FreeBSD.ORG Subject: Re: CD writers as a backup medium Message-ID: <Pine.BSF.4.01.9808011254190.295-100000@SchematiX.net> In-Reply-To: <19980801144333.A12731@fcc.net>
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On Sat, 1 Aug 1998, Nathan Dorfman wrote: > On Sat, Aug 01, 1998 at 10:10:29AM -0700, Scott wrote: > > > > > > On Sat, 1 Aug 1998, Nathan Dorfman wrote: > > > > > On Sat, Aug 01, 1998 at 06:04:01PM +1000, Andrew Bromage wrote: > > > > G'day all. > > > > > > > > Just wondered if anyone had thoughts on using a CD writer with > > > > FreeBSD-stable as a backup medium. Does the lack of hard real-timeness > > > > matter? Like, if some other process starts thrashing, will my CD be > > > > ruined? Is the support for some writers better than others? Should I > > > > just stick with tape? > > > > > > Yes, the lack of hard real-timeness matters. CD writers ideally > > > want a constant stream of data. Depending on the size of the buffer > > > in your drive, you can interrupt the stream for as much as a second > > > or two. However, if some other process starts thrashing and the CDR > > > drive's buffer *is* exhausted, there is nothing more to write and > > > you're SOL, as that CD is now a coaster. > > > > > > This is why people make filesystems on their hard disk and then burn > > > it to CD. However, if the system is mostly idle, and you have a fast > > > disk, you shouldn't have too many problems backing up to CD. You may > > > want to consider sticking to tape though. Tapes hold what, 4 gigs? > > > CD-ROMS hold 650MB. > > > > tapes may be 4GB, but most of them are extremely slow compared to a CD-R. > > Even some of the fastest tape drives aren't as fast as a 4x CD-R (last > > time i checked). Tape drives are also a lot more expensive and the tapes > > are EXTREMELY expensive. CD-R disk can be found for $1 or less if you have > > a rebate. Tapes for my TR1 drive (old; never in use anymore) are $30 > > each...and i have 5 tapes for them. So it really comes down to how much > > money you have. > > A 90 meter DAT tape can hold up to 4 gigs per tape. You can get them > for about $9 a piece, according to people who buy them. You'll need > 6 CDs to back up 4 gigs on CD, that's $6-9. Use the DAT tape twice > and you've already gotten your money's worth. A good CD-R drive is > $400 (SCSI). How much is a SCSI DAT drive, anyone? Plus, I'm not > even mentioning that you can buy 120m tapes for only a few dollars > more. The 7502 can be found for $269 or less for the bare drive. Its a 4x8 drive with 1MB or 2MB cache (can't remember). DAT drives are nice, but the drives are quite expensive. Plus, you can't beat the versatility of a CD-ROM. > > > -- > > > Nathan Dorfman | E-mail: nathan@fcc.net > > > Frontline Communications | Front desk: 914-623-8553: > > > > -scott > > -- > Nathan Dorfman | E-mail: nathan@fcc.net > Frontline Communications | Front desk: 914-623-8553: > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-stable" in the body of the message > To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message
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