[CentOS-mirror] recommendations for mirror server hardware?

[David Richardson]

On Tue, 27 Mar 2012, John 'Warthog9' Hawley wrote:

> As much ram as you can reasonably afford and fast, and large, disk.  The
> number of cores doesn't really play as much of a roll in a normal mirror
> as those two factors do.
>
> - John 'Warthog9 Hawley
>
> On 03/27/2012 02:40 PM, Tom Perrine wrote:
>> Does anyone have recommendations for server hardware?  Number of cores, RAM, storage?
>>
>> We've got the bandwidth, I just need to know what kind of server to get...
>>
>> --tep


A lot of it depends on how much traffic you want to be able to serve. If 
you want to be able to provide a few hundred megabits, you don't need a 
lot. If you want to handle kernel.org levels of traffic, you'll need 
something bigger. :)

Until about a year ago, my mirror was a 4-drive raid10 (of 7200rpm SATA 
drives) and 16GB RAM. It really doesn't take a lot.

The more traffic you can serve from RAM, the less disk throughput you 
need. Disk reads are *vastly* more important than writes. I would strongly 
recommend some level of drive redundancy, both to prevent you from needing 
to resync and to prevent trouble for your downstream clients.

As a slight aside, the most important bit of tuning I did was to change 
vm.vfs_cache_pressue (I set it to 10). This tells the kernel to keep the 
file metadata in RAM. It makes it so rsync doesn't have to churn the disk.

DR

-- 
David Richardson <david.richardson at utah.edu>
Center for High Performance Computing at the University of Utah