72 lines
4 KiB
Markdown
72 lines
4 KiB
Markdown
---
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date: 2013-02-25
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title: The Linux to Storage
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category: Opinions
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---
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Martin "Storagebod" Glassborow recently wrote an interesting article
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where he asked "Who'll do a Linux to Storage?". As someone who is
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equal parts Storage and Linux, the same question runs around my head
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quite often. Not just that, but how to do it. It is safe to say that all
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the constituent parts are already in the Open Source Ecosystem. It just
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needs someone to pull them all together wrap them up in an integrated
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interface (be that a GUI, CLI, an API or all).
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Linux, obviously, has excellent NFS support. Until recently it was a
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little lacking in terms of block support. [iSCSI Enterprise
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Target](https://sourceforge.net/projects/iscsitarget/) is ok, but is not
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packaged for RHEL, which for most shops makes it a big no-no. Likewise
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[TGT](https://stgt.sourceforge.net/) is not bad, I have certainly used
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it to to good effect, but administering it is a bit like pulling teeth.
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Additionally, neither are VMware certified and I am pretty sure that TGT
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at least is missing a required feature for certification as well (may be
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persistent reservations). There is a third SCSI target in Linux though:
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[LIO Kernel Target](https://www.linux-iscsi.org/) by Rising Tide
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Systems. This is a lot newer, but is already VMware Ready certified. Red
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Hat used it in RHEL6 for FCoE target support, but not for iSCSI. in
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RHEL7 they will be [using it for all block
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storage](https://groveronline.com/2012/11/tgtd-lio-in-rhel-7/). It has a
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much nicer interface than the other targets on Linux, using a very
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intuitive CLI, nice JSON config files and a rather handy API. Rising
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Tide are a bit of an unknown however, or at least I thought so. It turns
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our that both QNAP and Netgear use LIO Kernel Target in their larger
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devices - hence the VMware certification. In any case, Red Hat are
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behind it, although I think they are working on a fork of at least the
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CLI, so I think success is assured there. That solves the problem of
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block storage, be it iSCSI, Fibre-Channel, FCoE, Infiniband or even USB.
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Another important building block in an enterprise storage system is some
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way of distributing the data for both redunancy and performance. Marin
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mentions [Ceph](https://ceph.com/) which is an excellent system.
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Personally I would put my money on [GlusterFS](https://www.gluster.org/)
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though. I have had slightly better performance from it. Red Hat bought
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Gluster about a year ago, and have put some serious development effort
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into it. As well as POSIX access via Fuse, it has Object storage for use
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with OpenStack, a native Qemu connector is coming in the next versions.
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Hadoop can also access it directly. There is also a very good Puppet
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module for it, which gets around one of Martin's critisms of Ceph.
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Which brings me nicely to managing this theoretical system. Embedding
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Puppet in this sort of solution would also make sense. There will be
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need to a way of keep config sync'ed on all the nodes (I mentioned that
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this disruptive product will be scale-out didn't I? NO? OK, it will be
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-prediction for the day). Puppet does this already very well, so why
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re-invent the wheel.
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All this can sit on top of Btrfs allowing each node to have up to 16
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exabytes of local storage. For now I am not convinced by it, at least on
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RHEL 6 as I have seen numerous kernel panics, nor did I have a huge
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amount of joy on Fedora 17, but there is no doubt that it will get
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there. Alternatively, there is always the combination of XFS and LVM.
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XFS is getting on a bit now, but it has been revived by Red Hat in
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recent years and it is a proven performer with plenty of life left in it
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yet.
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After all that, who do I think is ripe to do some serious disrupting in
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the storage market? Who will "Do a Red Hat" as Martin puts it? Simple:
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it will be Red Hat! Look at the best of breed tools at every level of
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the storage stack on Linux and you will find it is either from Red Hat
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(Gluster) or they are heavily involved (LIO target). They have the
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resources and the market/mind share to do it. Also they have a long
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history of working with and feeding back to the community, so the
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fortuitous circle will continue.
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