Red Hat announces GFS 240
PSUdaemon writes "Over at Kernel Trap they have an announcment that Red Hat has released GFS under the GPL and offer it through RHN. This could potentially be a very substantial offering from Red Hat."
With your bare hands?!?
Re:Free for $2,200? (Score:1, Informative)
http://sources.redhat.com/cluster/
and for gfs sources go here..
http://sources.redhat.com/cluster/gfs/
Re:executive summary? (Score:5, Informative)
GFS (Global File System) is a cluster file system. It allows a cluster of computers to simultaneously use a block device that is shared between them (with FC, iSCSI, NBD, etc...). GFS reads and writes to the block device like a local filesystem, but also uses a lock module to allow the computers coordinate their I/O so filesystem consistency is maintained. One of the nifty features of GFS is perfect consistency -- changes made to the filesystem on one machine show up immediately on all other machines in the cluster.
and
GFS has no single point of failure, is incrementally scalable from one to hundreds of Red Hat Enterprise Linux servers, and works with all standard Linux applications.
Dunno if any other linux "file systems" have all that.
Re:Compatibility? (Score:5, Informative)
Of course it will, It's GPL and looking for inclusing into the kernel. Just like everything else from Red Hat. If you expect them to optimize it for SuSe, Mandrake, Gentoo you're mistaken but sometimes they supply Debian packages for things they write. If it doesn't get accepted upstream for whatever reason It's up to vendors to supply the packages, not the writer of the software.
Re:Free for $2,200? (Score:5, Informative)
Though in this case, you can download GFS and all the related software for free. Just go to the
cluster [redhat.com] project page.
GFS is cool! (Score:5, Informative)
yes, that's actually the basic idea (Score:4, Informative)
Now if, after running for some time, one of the machines gets coffee spilled on it and dies, GFS will automatically route around it. The result is that a slashdotter will not be aware of the failure, and still get the video.
Meanwhile you can fix the problem and bring the downed machine back on-line again.
Re:executive summary? (Score:5, Informative)
The GFS software lets files be stored in a single file system shared by numerous servers. The information can reside on servers themselves or on a storage area network.
The software is used to speed data access and replicate information so it's still available even if individual machines fail. It's useful for the two conventional types of clusters: groups of machines linked so one can take over for another in case of a problem, and groups linked as part of a sprawling supercomputer.
Red Hat GFS is tuned to work with Oracle's 9i RAC, database software that can spread across multiple clustered machines, and work with Red Hat's cluster software for ensuring services remain available despite computer problems.
GFS defined... (Score:5, Informative)
Red Hat Global File System (GFS) is an open source, POSIX-compliant cluster file system and volume manager that executes on Red Hat Enterprise Linux servers attached to a storage area network (SAN). It works on all major server and storage platforms supported by Red Hat. The leading (and first) cluster file system for Linux, Red Hat GFS has the most complete feature set, widest industry adoption, broadest application support, and best price/performance of any Linux cluster file system today.
Red Hat GFS allows Red Hat Enterprise Linux servers to simultaneously read and write to a single shared file system on the SAN, achieving high performance and reducing the complexity and overhead of managing redundant data copies. Red Hat GFS has no single point of failure, is incrementally scalable from one to hundreds of Red Hat Enterprise Linux servers, and works with all standard Linux applications.
Red Hat GFS is tightly integrated with Red Hat Enterprise Linux and distributed through Red Hat Network. This simplifies software installation, updates, and management. Applications such as Oracle 9i RAC, and workloads in cluster computing, file, web, and email serving can become easier to manage and achieve higher throughput and availability with Red Hat GFS.
Highlights
Performance
Red Hat GFS helps Red Hat Enterprise Linux servers achieve high IO throughput for demanding applications in database, file, and compute serving. Performance can be incrementally scaled for hundreds of Red Hat Enterprise Linux servers using Red Hat GFS and storage area networks constructed with iSCSI or Fibre Channel.
Availability
Red Hat GFS has no single-point-of-failure: any server, network, or storage component can be made redundant to allow continued operations despite failures. In addition, Red Hat GFS has features that allow reconfigurations such as file system and volume resizing to be made while the system remains on-line to increase system availability. Red Hat Cluster Suite can be used with GFS to move applications in the event of server failure or for routine server maintenance.
Ease of Management
Red Hat GFS allows fast, scalable, high througput access to a single shared file system, reducing management complexity by removing the need for data copying and maintaining multiple versions of data to insure fast access. Integrated with Red Hat Enterprise Linux (AS, ES, and WS) and Cluster Suite, delivered via Red Hat Network, and supported by Red Hat's award winning support team, Red Hat GFS is the world's leading cluster file system for Linux.
Advanced features
Scalable to hundreds of Red Hat Enterprise Linux servers. Integrated with Red Hat Enterprise Linux 3 and delivered via Red Hat Network, comprehensive service offerings, up to 24x7 with one-hour response. Supports Intel X86, Intel Itanium2, AMD AMD64, and Intel EM64T architectures. Works with Red Hat Cluster Suite to provide high availability for mission-critical applications. Quota system for cluster-wide storage capacity management. Direct IO support allows databases to achieve high performance without traditional file system overheads. Dynamic multi-pathing to route around switch or HBA failures in the storage area network. Dynamic capacity growth while the file system remains on-line and available. Can serve as a scalable alternative to NFS. Product Information Supported on Red Hat Enterprise Linux AS, ES, and WS. Red Hat Cluster Suite support available on Red Hat Enterprise Linux 3. Support for a wide variety of Fibre Channel and iSCSI storage area network products from leading switch, HBA, and storage array vendors. Mature, industry-leading, field-proven, open source cluster file system.
Re:Newbie (Score:4, Informative)
Newcomer? (Score:5, Informative)
Re:Free for $2,200? (Score:2, Informative)
GFS has a troubled license history (Score:4, Informative)
This move by Red Hat gives new life (and resources) to GFS beyond the OpenGFS Project [sourceforge.net] that has also been continuing to work on the code.
Another recent development in this area is HP's decision to productize Lustre [tmcnet.com]. Lustre [lustre.org] is perhaps the most prominent and promising HPC filesystem.
SGI also announced [linuxelectrons.com] a major deal last week involving Luster:
The new file system is expected to sustain write rates in excess of 8GB/sec and demonstrate single client write rates of more than 600MB/sec. To achieve this performance, the new file system will leverage Lustre, an open source, object-oriented file system with development lead by Cluster File System Inc., with funding from DOE. Lustre currently is used on four of the top five supercomputers, including the PNNL cluster based on 1,900 Intel® Itanium® 2 processors.
Re:executive summary? (Score:4, Informative)
Yes your architecture can be designed with a single point of failure. However, in practice you will want to connect this to a SAN. The SAN will be full of dually connected disks, have 2 main controllers, at least 2 power supplies, be connected to two switch banks via 2 HBA's, and each server will be connected to each switch. For added safety, direct connect another SAN to the first, and mirror all data between the SAN's.
But mainly, a good SAN is designed to be dually redundant from the ground up. Kind of like those (Fujitsu? Panasonic?) servers that have 2 standard mobo's in them and sync all data between cpu's, so if one dies the whole system is still alive.
What I need is a simple mirroring system for two failover servers, without single point of failure.
What kind of servers? The best method will depend on the type of server.
It's very frustrating. DFS and FRS seem to work just fine under Windows, so why hasn't Linux got it?
Because you haven't paid for it yet, be it in cash or time.
Re:executive summary? (Score:2, Informative)
For example, the boxes I used to work with were dual host adapter boxes with the RAID5 containers in RAID1 setup. Each box+adapter has two NICs, going to different switches. Each box has a three PSUs, going to different UPSs.
Using a simple setup like this, there simply is no single point of failure. Apart from the room they are in, obviously.
Cheap? No. Avoiding single points of failure completely is expensive. And mostly impossible. It's one of those risk/cost curves.
Re:Isnt free. So why do I care? (Score:3, Informative)
Not to YOU of course, because you have no need for such things.
Remember, it's Free Software. That means you can pay Red Hat for it and get their support. Don't want that, fine. Now the source is available, so you can download and compile it yourself, or print it out and wipe your ass with it. Or maybe your favorite distro will download it, package it, enhance it, and include it in their next release.
Re:Free for $2,200? (Score:2, Informative)
Re-read what you just posted.
It says the *license* under which you distribute it must make it available to third parties. The GPL does not require you to *distribute* the source code to anyone except those who receive the product in executable form. But because it is licensed to third parties, anyone in possession of the source code *may* distribute it to third parties.
-- TTK
Re:Difference between GFS, NFS and AFS? (Score:3, Informative)
I don't know much about AFS, but two significant differences between NFS and GFS:
GFS supports a global file locking interface; NFS does not. So for instance you can have a farm of web servers whose cgi scripts access/update shared files atomically, or multiple database servers which share the same database file, locking individual records to perform simultaneous INSERT/UPDATE transactions.
GFS supports host-granularity redundancy and failover; NFS does not. So if your NFS server bursts into flame, the filesystems it was exporting go away everywhere on your network, but your GFS systems can have two or more hosts exporting the same filesystem. This provides security not only against spontaneous combustion and other disasters, but also scheduled down-times. IT can power down one GFS server to replace a hard drive or move it to a different room, and the backup GFS servers will keep the exported filesystem available without interruption.
If GFS is more scalable/reliable than NFS, that would be nice, but I don't yet know if it does.
-- TTK
The Microsoft Effect (Score:4, Informative)
While it is amusing to see a MCSE struggling to configure Postgres or MaxDB (which can be a little tricky) and complaining about the lack of a GUI (I didn't have the heart to find and install the various GUIs for them...heh), it does not sit well with the PHB to see labor costs skyrocket with no discernable work being done (from their perspective).
The moral of this rant is: even though it is free software, that does not automatically mean that you should not have to pay for the expertise to setup, run, and maintane it. RedHat (and the other commercial distros) have excellent service and tend to service smaller companies at the same level MS only does for much larger companies. PHBs should be looking for gain in long term licensing costs and flexibility. No lock-in, no artificially driven need to upgrade, no technological sea change forced upon you.
Re:That exists for years already! (Score:3, Informative)
NFS on the other hand can be accessed from multiple machines but is ultimately hosted on one specific machine, giving you a single point of failure.
Re:yes, that's actually the basic idea (Score:5, Informative)
The best way to deliver this to the user (in this case, the slashdotter) would be to replicate this content onto a group of web servers using rsync(1). Each machine serves the content off of its local drive and can use its memory to cache/buffer the disk reads. In front of the web servers, you would put a wire-speed load balancer, such as an Nortel Alteon content switch [nortelnetworks.com] or a Foundry Networks ServerIron switch [foundrynet.com]. The load balancer, when configured properly will take care of monitoring your web servers. It would take me too long to explain it here, but these switches are sophisticated enough that they can take failed webservers out of the load-balancing group for everything from a ping failure to a content failure.
The key to designing web architectures is simplicity. Web serving does not need fancy clustering software or distributed filesystems. Very few web sites will not fit on the hard disk of your average 1U server. Keep it simple and put the intelligence up front in the switch.
What is GFS good for? Many things! It would be great for a large computational cluster that had a very large (multi-terabyte) dataset and high disk I/O requirements. Anything that has a requirement to provide one or more very large files to a number of cluster nodes would be perfect for GFS.
Chris
Re:I don't think so (Score:5, Informative)
Of course Red Hat doesn't support other distros, but what makes you think the clustering software doesn't work on them? All the bits and pieces are available for download [redhat.com]. If you find any "if (distro != RH) exit()" code in the fully GPL'd cluster toolchain, please feel free to remove them. There's no secret sauce to RHEL, it's all open source and everyone is free to copy and modify the code.
There's already one distro that includes the new GPL'ed GFS filesystem out as of today, Lineox [lineox.com]. And Red Hat will be working to get GFS up to spec for inclusion in the official Linux kernel according to posts made to the kernel mailing list.
The code itself is open source, that is true, but "Red Hat Enterprise Linux subscription [is] required"
This only refers to that point that Red Hat is not interested in selling to you unless you have a RHEL subscription. That $2,200 gets you GFS up and running on your RHEL cluster in a turnkey fashion, and it gives you the option to purchase further 24/7 one-hour response support contracts. You're free to assemble it all into a working system by yourself if you want.
Re:Not quite, but OpenAFS would be a good option (Score:4, Informative)
Re:I don't think so (Score:5, Informative)
I am personaly going to try installing GFS on some Debian systems for a U of M student group who recently got a donation of some used Fibre-Channel disk.
What I'm hoping for now is support for ia64, and other platforms. It would also be nice if GFS could now be ported to other OS's like AIS and Solaris.
Re:executive summary? (Score:3, Informative)
Re:Babbling? Where is the GPL link then. (Score:3, Informative)
No, that's to get a supported version. If you would actually read the announement linked to in the story, you'd get a link to where you can get the source code from cvs.
See also OpenGFS and OCFS (Score:4, Informative)
These may go away since their major reason for existing was that Sistina had closed up source for GFS.
Thanks RedHat. With LVM2, GFS, my EMC SAN and my cluster of Gentoo boxes (ya, sorry 'bout that part) I'm going to have lots of fun.
Re:... compared to InterMezzo, CODA or oMFS? (Score:3, Informative)
GFS instead gives everyone access to the same disk at the same time rather than replication. Both methods work well for different data sets - so yes GFS and oMFS are similar
Re:What is a SAN (Score:4, Informative)
A SAN can be a single large block device. The specifics will depend on the SAN, but you should be able to arrange the disks in any RAID configuration (or none), and present 1 or more block devices to 1 or more servers.
When I manipulate a sector on the disk, the SAN is actually manipulating the same sector on multiple identical drives.
Not necessarily the same sectors, depending on whether we're talking physical or logical sectors, but basically that's correct.
So from this standpoint, it sounds similar to RAID, except for the redundant power supplies.
Well most servers come with 2+ power supplies for fail-over, so even the redundant power supplies isn't different.
From the description, it sounds like SAN has another important difference from RAID. The SAN, redundant power supplies, redundant drives, and all, is a separate system from the computer.
There are disk arrays you can buy that direct attach to computers. These too would be separate units from the computer (benefit: if the computer dies, reattach the pack to a separate computer. A lot simpler than having to remove/insert each disk).
Unlike RAID, which pretends to be a single block device, the SAN can be accessed by multiple CPU's.
Depending on the RAID device, you can configure multiple logical devices across multiple physical devices. Dell's PERC's generally allow this (ok, not across separate disks, but if there are 10 disks, you could have 2 sets of 5 disks in RAID5).
A RAID device can be accessed by multiple CPU's in the case of a 2+ way server. So, you mean multiple servers, not multiple servers.
A SAN can be connected to many servers - 64, 128, 1024, etc, depending on the SAN and your budget.
(Therefore, you don't want to put an ordinary filesystem onto it, such as Ext3.) Therefore the design of GFS, which allows multiple cpu's to concurrently manipulate the filesystem.
Yes, the FS will depend on the use. If you can hookup multiple servers to the same disk, then you need an FS that can handle that. If you are planning on dynamically growing the device, then you need an FS that can handle that.
Do I fundamentally misunderstand?
Parts you understand. A SAN also has many other uses, like disk consolidation, functionality, and management, but these issues and uses will really depend on your environment.
For example, if you generally buy a server with a bunch of disk in case you ever need it, then you probably have a big range of % use on your servers. A SAN lets you consolidate that disk space in one place. Perhaps you have one server running at 30% total disk use, another at 99%, and another at 50%. Would be nice to dynamically allocate the disk from the unused servers to the disk on the 99%, but barring inefficient methods, this is very, very difficult. With a SAN, i can grow those disk devices on the fly and make sure each server always has X amount free (probably around 20% free space). When you're talking about many servers, or lots of unused space, this can add up to a big ROI.
Or, let's say you use a proprietary FS like Veritas for your Enterprise servers. Buying automatic mirroring for those servers may add up to a lot of money, so instead invest once in your SAN's disk mirroring product and use this for those servers (yeah this may be just as or more costly, depending on your SAN).
And there are other functionalities, like server independant snapshots and mirrors - your FS may handle snaps or mirroring, but can a separate server mount that? With a SAN, that can be possible. Imagine your webserver mounts a RO mirror of the data that is only changeable via a more protected server. You could do that via NFS, but it would come at a speed cost. With the SAN, you're not limited to the
Re:... compared to InterMezzo, CODA or oMFS? (Score:5, Informative)
Now imagine a filesystem designed for servers that allows them to access the filesystem at a block level directly via the shared bus. Let's say a parallel SCSI buss (or any bus that allows more than one host, e.g. iSCSI, Fibre Channel, Firewire). Imagine how fast it would be to access a shared disk over Fibre Channel! The problem is that if two servers mount the filesystem at the same time it would normally currupt the filesystem. People with SAN's (Storage Area Networks) solve this problem by making mini virtual hard drives and setting ACL's on them so only one host can access that virtual hard drive at a time. This could lead to a waste of space.
GFS solves the SAN problem by using a Distributed Lock Manager (DLM). No one host is the server of the filesystem, but writes/locks are coordinated via the DLM. Now multiple hosts *can* share a virtual hard drive or real block device and not corrupt the filesystem. If a host dies, no problem, there is no server for the filesystem!
Let's give an example. Say you have a firewire enclosure. Now plug that firewire hard drive into two computers. This, by the way, may still require a patch to sbp so that Linux will tell the enclosure to allow both hosts to talk to it at the same time. Now that the hard drive is talking to both computers you could run GFS on it and access the data at the block level by both systems. Now start serving email via IMAP (load balanced), *both hot*, no standby. Now kill a box. IMAP still works. No remounting, no resycronization.
Pretty amazing if you ask me! This technology is pretty rare. IBM has GPFS. SGI has Clustered XFS. Both are pretty expensive. GFS? RedHat just re-GPL'd it! Microsoft? Ummm. I think they are just now getting logical volume management.
GFS also has nice features like journaling (kinda required for this sorta thing), ACL's, quotas, and online resizing.
Now tell me Linux isn't enterprise!
Yes, it does. (Score:3, Informative)