🚀 go-pugleaf

In article <55kgmk$7l9@bunyip.cc.uq.oz.au>,
David Conran <lucifer@maths.uq.edu.au> wrote:
>ian@ilm.mech.unsw.edu.au (Ian Maclaine-cross) writes:
>
>>>
>>>Be sure of what you are saying/offering before you do :)
>>>Having setup the linux mirror at ftp.dstc.edu.au (yes .. it was my baby)
>>>I can tell you, a *lot* of effort goes in to maintain it. Much more
>>>than you imagine.
>
>>A belated thanks for your efforts, David! 
>
>>I suggest to anyone who is thinking of mirroring Linux that
>>they consider using a Linux box. ftp.cdrom.com is based on Pentiums.
>>CTAN.unsw.edu.au is also a Pentium based mirror running Linux (Debian
>>1.1). For a 10GB mirror the Pentium hardware is under $3000 and the
>>software is free. 
>
>Hmmm .. bet you it costs a fair bit more to go beyond 4 x 3.5 Gb disks :)
>(At least with scsi you can get up to 7 devices (excluding host) per bus and
>have multiple busses)

If you want a 30 GB mirror, consider two Linux Pentium boxes each with
4 x 4 GB disks. Link them with NFS and the client will never know the
difference. About $6000. Maybe a really large busy site like
ftp.cdrom.com needs SCSI but if your link to the net is only 10 MHz
why bother?

>>We do not backup CTAN, it is a mirror not an archive.  Index and ls-lR
>>files are locally generated after the ls-lR.Z file is downloaded from
>>ftp.tex.ac.uk. We use a similar technique with our partial mirror of
>>Debian. 
>
>Ah ... we didn't back ftp.dstc.edu.au for a long while ... and then we had
>a disk failure(s). It took 3 months to get back upto date with the mirror.

CTAN is about 2.3 MB and took a month to download from the UK. It
downloaded the most recent files first. 

We need multiple *accurate* mirrors in Australia of important overseas
sites. If one crashes it may be only days to bring it up again by
mirroring a local site.

>I strongly suggest to anyone they take atleast weekly full backups of there
>linux mirror. It is way too slow re-get the entire linux mirror.

If you are running an archive (or source site) backups are
essential. The labour and cost of tape backups is prohibitive for a
mirror. 

Much better to share the load by having a nearby secondary mirror paid
for and run by someone else. If your site crashes, you backload from
them first.

BTW: If anyone wishes to mirror the full CTAN and has a Pentium
running Debian with a 10 MHz connection to the net, please email me
and I will help them with scripts. The scripts for a local secondary
mirror are simpler than for a primary mirror.

>(And now a days .. cost you a small fortune ;)

The idea of mirroring is to save communication costs. It is done
when the net is idle so its marginal cost is nothing. If you are
paying through the nose for this you need a new service providor.

-- 
Regards,
Ian Maclaine-cross (ian@ilm.mech.unsw.edu.au)