Gentoo Archives: gentoo-user

From: "Norman Rieß" <norman@×××××××××.org>
To: gentoo-user@l.g.o
Subject: Re: [gentoo-user] Linux Fiber SAN
Date: Thu, 13 Jun 2013 04:59:16
In Reply to: Re: [gentoo-user] Linux Fiber SAN by Nick Khamis
1 Am 12.06.2013 16:20, schrieb Nick Khamis:
2 > Hello Nick,
3 >
4 > the question is, what are you doing with it and why do you think you
5 > need a fibre channel SAN.
6 > Our goal indeed is to get rid of the SAN infrastructure as it is
7 > delicately to all kinds of failure with nearly zero fault tolerance.
8 > An example, you have an hicup or a power failure in your network. SAN is
9 > dead from nowon and must be reinitialized on the server. Simple NFS
10 > comes back up without any fuzz.
11 > Another, you boot your storage systems due to an os update or something
12 > like that. Your SAN will be dead. NFS will just go on as if nothing
13 > happened.
14 > We use netapp storage systems which are NAS and SAN capable.
15 > Another point is, that if you have a SAN lun, there is either no way to
16 > increase or decrease size on the fly, on cifs or nfs you can resize your
17 > share on the go.
18 >
19 > So if you do not have a _really_ good reason to use a fribre channel
20 > SAN, don't!
21 >
22 > Regards,
23 > Norman
24 >
25 >
26 > Hello Norman,
27 >
28 > Thank you so much for your response. That is a very interesting! We
29 > currently use an NFS to house home directories etc.., and I love how it
30 > just bloody works!!! We do however need block level sharing. The idea is
31 > the
32 > typical host with multiple VM with virtual HDDs residing on a SAN.....
33 > We figured
34 > fibre would give us better performance (for the mean time!!!).
35 >
36 > It was my understanding that SAN whether implemented using iSCSI
37 > or Fibre was essentially susceptible to the same type
38 > of faults that lead to whatever failures? The only difference being of
39 > course, on is on fibre, and the other using ethernet. Given the price
40 > of fibre right now, it's quite cheap and we though double the throughput,
41 > why not?
42 >
43 > We could have the VMs taking storage from DAS, and mount to an
44 > external NFS for home/ etc... Not sure how it would perform in terms of
45 > IO rates, and also, the idea of block level allocation just seems so much
46 > cleaner no?
47 >
48 > PS I am new to SAN, please excuse me.
49 >
50 > Kind Regards,
51 >
52 > Nick
54 Hello,
56 our setup is that we open up pools of up to 20 hosts which all mount the
57 same NFS share which holds sparse file images as virtual hdds of the
58 VMs. So life migration is possible, other than holding the VMs on local
59 storage.
60 Our never clusters are equipped with hosts using 10 gigabit ethernet.
61 Two 10GE ports are bonded to provide redundancy and balancing. Every
62 host features 2 bonds, one for storage vlans and one for the production
63 vlans. Performance is not the issue.
64 Our older clusters do this with 1 gigabit ethernet and three bonds.
65 We have some high performance services and throughput never was a problem.
66 So i recomment NFS. But it really depends on your prefferation.
68 Regards,
69 Norman


Subject Author
Re: [gentoo-user] Linux Fiber SAN Nick Khamis <symack@×××××.com>