Hi, Simon pointed out that we fill this with 4TB disks for only £100 more, so I suggest that we go with that as I have had no other feedback. I propose that we buy this now and have it ready in time for the summer projects on the MSc course. Kenny, are you happy with this? If so we should go ahead and order. Best, david On 10/03/15 15:20, David Colling wrote:
Hi Adrian,
I suspect that we start off with the 4 disc unit with the explicit understanding that this is a "pump primer". I suspect that with 4 discs we would run RAID 10 so as to have striping and resilience. Looking at the specs it appears that there are 2 GigE ports so we should be OK (anything bigger and we would need 10Gb/s).
This would only give us 4TB which seems very small to me but I don't think that we would fill anything bigger for a couple of years. Although I really would welcome input from others.
Best, david
On 09/03/15 12:59, Mannall, Adrian B wrote:
Hi David,
If you really want to start small then you could go with a 4 drive bay unit such as the following (contains 4 x 2TB drives) which could be run in RAID5 or RAID6 (possibly overkill for a 4 drive unit). Pricing is around £1,200 + VAT and includes a 5yr warranty on hardware.
http://www.businessdirect.bt.com/products/netgear---------readynas-2120-1u-4...
Bigger units are as one would expect more expensive ... a 12 x 2TB unit would cost just shy of £6,000 + VAT but would give you nigh on 20TB of usable space in a RAID6 array ... http://www.businessdirect.bt.com/products/netgear-readynas--4200-12-bay-2u12...
Regards Adrian.
-----Original Message----- From: David Colling [mailto:d.colling@imperial.ac.uk] Sent: 09 March 2015 12:54 To: Mannall, Adrian B; physics-departmental-computing; Sedgbeer, Julia K; Weir, Kenny Subject: Re: [Physics-Departmental-Computing] Storage for UG projects
Hi Adrian,
What would be the (rough) cost of such a system? Don't forget that we are looking for a low cost solution that start the system going with the full expectation of buying a proper server in a few years time. At this stage we were looking more atth 4TB usuable rather than the 20 unless the cost is very "reasonable".
best, david
On 07/03/15 18:22, Mannall, Adrian B wrote:
Hi David,
I think that what you are after falls in the current "grey area" for ICT. More than a few hundred GB but not a full blown SAN / NAS system.
I'd probably be inclined to suggest a NetGear ReadyNAS system as there are quite a few of those around, so we have some experience of working with them and the great thing is that we know we can bind them into the Active Directory and use SMB mounts for all users and ensure sensible access groups are created for data access and security.
We can also set up a management group which can be emailed by the unit for alerting (e.g. problems, disk failures, etc). The sensible option would probably be a 12bay unit with 2TB disks in all bays (to give you just shy of 20TB of actual usable space) in a RAID6 configuration. We could then set up appropriate shares (either by year or research group area) with a named person or persons to manage the group access, etc.
Content can then be controlled and managed by the project / groups concerned.
The reason for suggesting a full disk array is that adding disks later is possible but it can create issues if you extend by a large amount - OS needs re-initialising, at which point there's a lot of shuffling of files and data to allow a full factory reset to then utilise a larger disk array!
You can populate with 3TB, 4TB or even 6TB drives but it would make sense not to make the array too big. It might be more sensible to buy a second unit as storage requirements increase and move a few projects onto a second box rather than increase capacity in the first unit.
Regards Adrian
-----Original Message----- From: physics-departmental-computing-bounces@imperial.ac.uk [mailto:physics-departmental-computing-bounces@imperial.ac.uk] On Behalf Of David Colling Sent: 06 March 2015 15:55 To: physics-departmental-computing; Sedgbeer, Julia K Subject: [Physics-Departmental-Computing] Storage for UG projects
Hi,
At our last meeting we discussed getting some disk space for UG projects that would be visible to jobs running on the condor pool.
This afternoon Julia and I discussed this with Kenny and while we all agreed that it was a good idea we felt that it was a little bit of a chicken and egg situation. People wouldn't use immediately because they weren't used to using it and so it would take to become useful. If physics paid several £k for a server with (say) 40TB of usable space now it would already be close to being obsolete by the time people were really starting to use it in 3 or 4 years time and so most of the value would be wasted.
So instead we thought that a having a smaller unit that people can start to use but expecting it to be upgraded to to a full server when usage took off. So what we are looking for is something with a few TB of disc space, machine managed by ICT content managed by physics. At a very basic level this could be a machine with just 2 x 4TB disk with RAID 1 ... however I think that ICT should suggest a cost effective solution as we are asking them to manage it. This would provide a testbed for projects and would be replaced by a larger server as usage grew.
What do others (especially ICT) think about this suggestion?
Best, david
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