Re: Storage server
On Sat, Sep 08, 2012 at 09:53:33PM +0200, Martin Steigerwald wrote:
> For rsnapshot in my experience you need monitoring cause if it fails it
> just complains to its log file and even just puts the rsync error code
> without the actual error message there last I checked.
>
> Let monitoring check whether daily.0 is not older than 24 hours.
Didn't know that. Thanks, I'll monitor it if I opt for rsnapshot.
> Did you consider putting those webservers into some bigger virtualization
> host and then let them use NFS exports for central storage provided by
> some server(s) that are freed by this? You may even free up a dedicated
> machine for monitoring and another one for the backup ;).
No, they have to remain where they are, on physical remote locations.
> > Dedicated servers that will be backed up are ~500GB in size.
>
> How many are they?
5 of them and all 500GB total.
>
> > b) monitoring (Icinga or Zabbix) of dedicated servers.
>
> Then who monitors the backup? It ideally should be a different server than
> this multi-purpose-do-everything-and-feed-the-dog machine your are talking
> about.
Like I said, they should be on HA system, but I don't get to work in
ideally conditions. If my boss can live with it, so can I. I told him of
possible consequences and that's all I can do.
> > c) file sharing for employees (mainly small text files). I don't
> > expect this to be resource hog.
>
> Another completely different workload.
>
> Where do you intend the backup for these files? I obviously wouldn´t put it
> on the same machine as the fileserver.
>
> See how mixing lots of stuff into one machine makes things complicated?
I shouldn't mention this one. It's not workload at all. It's few MB
(~10) that will be downloaded periodically by other employees. It
doesn't have to be backed up.
As for complicating, I root for clean and simple, but if my job requires
to struggle with complicated things, I'll just have to do it. Not my
choice anyway.
>
> 4 GiB RAM of RAM for a virtualization host that also does backup and
> fileservices? You aren´t kidding me, are you? If using KVM I at least
> suggest to activate kernel same page merging.
>
> Fast storage also depends on cache memory, which the machine will lack if
> you fill it with virtual machines.
>
> And yes as explained already yet another different workload.
>
> Even this ThinkPad T520 has more RAM, 8 GiB, and I just occasionaly fire up
> some virtual machines.
Yes, I use KVM. I never intended to fill it with virtual machines. Like
I already explained, I intended to periodically use virtual machine with
300MB of RAM. That can't be amount of memory to suffocate host machine
with 4GB. And as I said, RAM is cheap and can be added if 4GB is not
enough.
> Well extension of RAID needs some thinking ahead.
That's why I'm here. ;)
> While you can just add
> disks to add capacity – not redundancy – into an existing RAID the risks
> of a non recoverable failure of the RAID increases. How do you intend to
> grow the RAID? And to what maximum size?
>
> At least you do not intend to use RAID-5 or something like that. See
>
> http://baarf.com
At my previous place of employment I worked with IBM storage that was
attached with optic cables via Brocade 4GB switch to load balanced
system. Storage provided shared block storage with GFS on it.
Performance sucked. And this was production mail server. I learned hard
way, no GFS ever again. Don't know if GFS2 is any better.
Same goes with RAID5. Had a Qnap nas server with RAID5. It was backup
server. It got things done, but performance was terrible. No data loss,
but this just sucked. Moral of the story for me was: don't use RAID5.
> So the customer is willing to use dedicated servers for different web sites
> and other services, but more than one machine for the workloads you
> described above is too much?
>
> Sorry, I do not get this.
Not that hard to comprehend. My boss sees backup as necessary evil. And
only after I pushed it. Before I got here, there was no backup. None
whatsover. I was baffled. And I had situation few days on my arrival,
that one of databases got corrupted. Managed to find some old backup and
with data we already had saved, restored database. But that situation is
not acceptable. I had to push things and to propose some cheap solution,
so I can have something I can work with.
> Serious and honest consulting here IMHO includes exposing the risks of
> such a setup in an absolutely clear to comprehend way to those managers.
Already did that.
> Are these managers willing to probably loose the backup and face a several
> day downtime of fileserver, backup and monitoring services in case of a
> failure of this desktop class machine?
They didn't have any backup, monitoring and that file sharing is done
now using someones windows share dir. This would be a huge step forward
for them.
> If so, if I would be in the position to say no, I would just say "no
> thanks, search yourself a different idiot for setting up such an insane
> setup". I understand, you probably do not feel yourself being in that
> position…
Exactly, I'm not.
Regards,
Veljko
Reply to: