On 10 Jul 1999, Osma Ahvenlampi wrote:
> Gordon Henderson <[EMAIL PROTECTED]> writes:
> > So does no-one apart from me use Amanda?
>
> Amanda's main problem is that it depends on tar or dump, and neither
> is all that great. Especially dump on Linux has major problems (no
> multivolume backups, no proper end-of-tape detection (which means
> trouble on at least Sony and Seagate drives), no software compression
You must be a lot behind the times - Amanda has supported compress and
gzip for a long time now (and I suspect it'd handle bz2 too if I had the
time to look into it). It also seems to correctly detect the end of tape -
at least on 2 different systems I have here - a Solaris box with a DLT4000
(20GB non compressed) and a Linux box with a 12 GB (non compressed) DAT
tape (on an adaptec controller - supersceded with a new Linux box with a
35GB DTL drive which hsn't filled up yet!) It does the right thing (as far
sa it's concerned) and aborts the dump at that stage.
Amanda doesn't actually use tar or dump to write the data to tape, it has
it's own tape writer which recieves the (stdout) output of tar or dump and
in theory can handle multiple tapes via tape jukeboxes, but I've no
experience of using them. (And I suspect that what you are probably saying
is that the volume can't be split over a tape - so it's no-use trying to
backup a 40GB drive onto 20GB tapes...)
Yes, Tar isn't great for extracting files from backup, however dump and
restore are - which I've had to use (too many times) in the past when
lusers delete files )-:
I've not (yet) at this site had a drive fail me and had to restore it from
backup (all my main filestores here are in RAID, so hopefully I won't ever
need to!), but I have done so in the past and it's not that difficult,
even with multiple levels of backup to apply.
> (which is absolutely necessary if you want to compress AND need to
> know how much data fits on one tape) and so on)..
>
> I've recommended Arkeia before, and I'll recommend it again. Good
> feature set, reliable, supports many platforms, and is surprisingly
> inexpensive as commercial backup software goes. Check
> www.arkeia.com. I have no other relation to them except as a satisfied
> customer.
I really don't like their front-page claim that speeds are 200-300% faster
than rival software packages. Perhaps they are just refering to commercial
packages (Amanda is free, how much is Arkeia?) I regularly get tape dump
rates of over 7MB/sec which to a tape drive that supports a max stream
rate of 5Mb/sec (I'm letting the tape drive compress my data for the time
being) is going quiet well. I'd love to see a 300% speed increase to that
when the hardware can't physically go any faster :-)
Gordon
