Date: Tue, 21 Jul 2009 17:43:40 -0400 From: "Christopher J. Umina" <chris.umina@studsvikscandpower.com> To: Grant Peel <gpeel@thenetnow.com> Cc: questions@freebsd.org Subject: Re: NFS- SAN - FreeBSD Message-ID: <4A66368C.3010009@studsvikscandpower.com> In-Reply-To: <26D9A85FF5344B9CA8F5DCDA1AFFBC46@GRANT> References: <25A3192F31A344B99F50583BDC58C921@GRANT> <C4577BCC84D24FFE97FD4036C2C4FB82@GRANT> <f151ba00907201321x363de61ai27c54d4902d1d9fc@mail.gmail.com> <85A4A9F5895D4CDCAEDF23E8181A118D@GRANT> <4A6535A2.90707@studsvikscandpower.com> <26D9A85FF5344B9CA8F5DCDA1AFFBC46@GRANT>
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Grant, I mean to say that often times external SCSI solutions (direct attached) are cheaper and perform better (in terms of I/O) than iSCSI SANs. Especially if you're using many disks. SANs are generally chosen for the ability to be split into LUNs for different servers. Think of it as a disk which you can partition and serve out to servers on a per-partition basis, over Ethernet. That's essentially what an iSCSI SAN does. While DAS systems allow the same sort of configuration, they don't serve out over Ethernet, only SCSI/SAS. Since you plan to use NFS to share the files to the other servers, I think it may make more sense for you to use a SCSI solution if yo don't need the versatility of a SAN. Of course I know nothing of how you plan to expand this system, but from what I understand, with Dell DAS hardware it is possible to connect up to 4 different servers to the DAS and expand to up to 6 15 disk enclosures. The MD3000i (iSCSI) expands only to 3. Another issue is that without compiling in special versions of the iSCSI initiator, even in 8.0-BETA2 (which is not production-ready), iSCSI performance and reliability are terrible. There are other versions of the code (which I currently use) for the iscsi_initiator kernel module, but unless you're comfortable doing that, you may consider DAS in terms of ease of implementation and maintenance as well. Chris Grant Peel wrote: > Chris, > > I don't know what a direct attached array is..... > > What I was just thinking was move all of the servers /home directory > to a huge NFS mount. > > If you have the time to elaborate fursther, I would apprciate it... > > This iSCSI think has me entrigued, but I must admit I know little > about it at this point. > > -Grant > > ----- Original Message ----- From: "Christopher J. Umina" > <chris.umina@studsvik.com> > To: "Grant Peel" <gpeel@thenetnow.com> > Sent: Monday, July 20, 2009 11:27 PM > Subject: Re: NFS- SAN - FreeBSD > > >> Grant, >> >> I have to ask, is there a reason you're intent on going with a SAN >> versus a direct-attached array? >> >> Chris >> >> Grant Peel wrote: >>> Thanks for the reply. >>> >>> I have not used/investigated the iSCSI thing yet.... >>> >>> The original question is can I just use an NFS mount to the >>> storage's /home partition? >>> >>> -Grant >>> ----- Original Message ----- From: mojo fms To: Grant Peel Cc: >>> freebsd-questions@freebsd.org Sent: Monday, July 20, 2009 4:21 PM >>> Subject: Re: NFS- SAN - FreeBSD >>> >>> >>> You would be better off at least having the SAN on 1gb ethernet or >>> even better tripple 1gb (on a 100mb switch should be fine but you >>> need failover for higher avaliability) ethernet for latency and >>> failover reasons with a hot backup on the network controller. I >>> dont see why you could not do this, its just iscsi connection >>> normally so there is not a big issue getting freebsd to connect to >>> it. We run 2 of the 16tb powervault which does pretty well for >>> storage, one runs everything and the other is a replicated offsite >>> backup. Performance wise, it really depends on how many servers you >>> have pulling data from the SAN and how hard the IO works on the >>> current servers. If you have 100 servers you might push the IO a >>> bit but but it should be fine if your not serving more than 2Mb/s >>> out to everyone, the servers and disks are going to cache a fair >>> amount of always used data. >>> >>> >>> On Mon, Jul 20, 2009 at 11:52 AM, Grant Peel <gpeel@thenetnow.com> >>> wrote: >>> >>> Hi all, >>> >>> I am assuming by the lack of response, my question to too long >>> winded, let me re-phrase: >>> >>> What kind of performance might I expect if I load FreeBSD 7.2 on >>> a 24 disk, Dell PowerVault when its only mission is to serve as a >>> local area storage unit (/home). Obviously, to store all users /home >>> data. Throug an NFS connection via fast (100m/b) ethernet. Each >>> connecting server (6) contain about 200 domains? >>> >>> -Grant >>> >>> ----- Original Message ----- From: "Grant Peel" >>> <gpeel@thenetnow.com> >>> To: <freebsd-questions@freebsd.org> >>> Sent: Saturday, July 18, 2009 10:35 AM >>> Subject: NFS- SAN - FreeBSD >>> >>> >>> >>> Hi all, >>> >>> Up to this point, all of our servers are standalone, i.e. all >>> services and software required are installed on each local server. >>> >>> Apache, Exim, vm-pop3d, Mysql, etc etc. >>> >>> Each local server is connected to the Inet via a VLAN (WAN), >>> to our colo's switch. >>> >>> Each server contains about 300 domains, each domain has its >>> own IP. >>> >>> Each sever is also connected to a VLAN (LAN) via the same >>> (Dell 48 Port managed switch). >>> >>> We have been considering consolidating all users data from >>> each server to a central (local), storage unit. >>> >>> While I do have active nfs's running (for backups etc), on the >>> LAN only, I have never attempted to create 1 mass storage unit. >>> >>> So I suppose the questions are: >>> >>> 1) Is there any specific hardware that anyone might >>> reccommend? I want to stick with FreeBSD as the OS as I am quite >>> comfortable admining it, >>> >>> 2) Would anyone reccomend NOT using FreeBSD? Why? >>> >>> 3) Assuming I am using FreeBSD as the storage systems OS, >>> could NFS simply be used? >>> >>> 4) Considering out whole Inet traffic runs about 2 Mb/s, is >>> there any reason the port to the Storage unit should be more than >>> 100 M/b (would it be imparative to use 1 G/b transfer)? >>> >>> TIA, >>> >>> -Grant >>> >>> _______________________________________________ >>> freebsd-questions@freebsd.org mailing list >>> http://lists.freebsd.org/mailman/listinfo/freebsd-questions >>> To unsubscribe, send any mail to >>> "freebsd-questions-unsubscribe@freebsd.org" >>> >>> >>> >>> >>> >>> _______________________________________________ >>> freebsd-questions@freebsd.org mailing list >>> http://lists.freebsd.org/mailman/listinfo/freebsd-questions >>> To unsubscribe, send any mail to >>> "freebsd-questions-unsubscribe@freebsd.org" >>> >>> >>> >>> >>> >>> -- Who knew >>> _______________________________________________ >>> freebsd-questions@freebsd.org mailing list >>> http://lists.freebsd.org/mailman/listinfo/freebsd-questions >>> To unsubscribe, send any mail to >>> "freebsd-questions-unsubscribe@freebsd.org" >>> >> >> > > > >
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