On 3/18/11, radoslav hodnicak <rh at 4096.sk> wrote:
> On Fri, Mar 18, 2011 at 10:07 AM, Randal L. Schwartz
> <merlyn at stonehenge.com> wrote:
>
>> radoslav> I'd argue for renting another machine from them instead of a
>> radoslav> VPS - why pay more for less? The current Hetzner servers (EQ
>> radoslav> line) start at quadcore cpu/8gigs of RAM for 49
>> radoslav> euro/month. How much would you pay to get that virtualized?
>> radoslav> Especially the memory tends to be a problem with smalltalks
>> radoslav> and VPSs.
>>
>> Take a look at the prices at arpnetworks.com/vps.  I'm also able to
>> negotiate some discount over that in exchange for publicity.  And I'd
>> rather have a VPS than a hard machine... if one machine goes down, it's
>> up to me to migrate, and immediately.  If a VPS host goes down, the
>> hoster has an obligation to launch my VPS on another box.  Just one more
>> way to keep a good SLA.
>
> I'm looking at the prices. I'd imagine squeak.org needs a machine that
> has at least 2gigs of ram to run the various squeak images, which is
> 60 bucks at ARP.
>
> 60 bucks at ARP gets you
> 2gigs RAM
> 60gigs disk space
> 600gigs traffic
>
> ~65 bucks at Hetzner gets you
> 8gigs RAM
> 750gigs disk space
> 5000gigs traffic
>
> I'm not against a virtual machine per se, but those ARP prices don't
> look appealing to me. And let me repeat that services written in
> squeak tend to be memory hungry.
>
>>> Also, doesn't the current machine have disks in raid0? That's the
>>
>> Raid0 only gives faster read and write performance. It decreases the
>> reliability of the system.
>
> Er yeah, I meant mirror. I always get the numbers mixed up
>
> rado


So you meant Raid 1 --- a server is supposed to have redundancy in the
harddisk otherwise it would not be a server.

http://en.wikipedia.org/wiki/RAID#Standard_levels
RAID 0 (block-level striping without parity  or mirroring) has no (or
zero) redundancy.

"0"   NO redundancy

In RAID 1 (mirroring without parity or striping), data is written
identically to multiple disks (a "mirrored set").

And MOST IMPORTANT
http://en.wikipedia.org/wiki/RAID#Data_backup

"A RAID system used as a main system disk is not intended as a
replacement for backing up data. In parity configurations it will
provide a backup-like feature to protect from catastrophic data loss
caused by physical damage or errors on a single drive. Many other
features of backup systems cannot be provided by RAID arrays alone.
The most notable is the ability to restore an earlier version of data,
which is needed to protect against software errors causing unwanted
data to be written to the disk, and to recover from user error or
malicious deletion."

Conclusion:
So actually a backup should not be too frequent if it only has one
version; e.g. a daily or weekly backup would be fine.


--Hannes