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<p>On 2014-02-03 10:23, Philippe Schwarz wrote:</p>
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<pre>1. A pair of Dell MD1200 (Disk enclosure with 12 SAS disks in a
stripped mirror) connected with SAS cables to each of the blades
(M620) in a M1000E enclosure.
Pros :
- -Simple
- - Max IOPS
- - Each storage is local for proxmox's point of view (Am i wrong ??)
Cons:
- -Difficult to scale : Up to three blades, it could be easy but after 4
ou 5 blades, there won't be enough ports on the SAS disk enclosure.
2.The same pair of MD1200 connected to a blade, acting as a ZFS-SAN
for the other blades and exporting (NFS or iSCSI) the storage content
in an external 10 Gbe connection.
Pros:
- - Easy to scale
- - Euh...ZFS ;-)
Cons:
- - More complicated
- - Less IOPS due to the 10Gbe link
- - More expensive (1 10GBE/blade+1 for the SAN+1 10GBE switch)
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<p> </p>
<p>Neither solution will work, since there's no way to physically connect external SAS disks to an M620 blade.</p>
<p>The M620 does not have external SAS ports, and it also lacks a PCIe slot for a SAS HBA.</p>
<p>The only M1000 blade that can connect to a SAS enclosure would be an M610x with an add-in PERC card. This would be an extremely strange configuration, to say the least, and is not supported.</p>
<p>Blade servers are explicitly *not* supported with the PERC H800 cards, as documented here: http://www.dell.com/learn/us/en/04/campaigns/dell-raid-controllers?c=us&l=en&s=bsd&cs=04&redirect=1.</p>
<p>However, even if it were possible to connect these components together, the first solution still will not work. The MD1200 does not support multi-initiator configurations; the dual (not triple) SAS ports can only be connected to two SAS ports on the same PERC card, and the PERC card must explicitly support the MD1200.</p>
<p>Sorry to burst your bubble, but you need to go back to square one with this... there's so much wrong with your solution I can't even suggest how to fix it!</p>
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<p>BTW, if you already have an M1000e chassis, you should probably be looking at the Equallogic PS 4110M iSCSI array instead. If you don't already own a M1000e chassis, purchasing one to hold only three blades is... well... stupid. You could buy 1U servers (and two MD1200s, and a 10GE switch) to do the same thing for around 1/4 the price.</p>
<p>If you really want blade-like equipement, look at the C6220 instead. That will give you four servers in a smaller footprint that doesn't require an electrician to hook up. Add whatever SAS or 10GE or ... cards you want; each node has a PCIe slot as well as two(?) mezzanine slots.</p>
<p>-Adam Thompson<br /> athompso@athompso.net</p>
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