There are two different versions of the Xsan 1.1 software upgrades. One is available for 10.3.9 while the other is for 10.4. Upgrade instructions from Xsan 1.0 on 10.3.x to Xsan 1.1 on 10.3.9 are: Backup the Xsan completely Unmount the Xsan volumes Upgrade the Operating System on the Primary Metadata Controller. Upgrade the Operating System on the Backup Metadata Controller. Upgrade the Xsan Software on the Backup Metadata Controller. Upgrade the Xsan Software on the Backup Metadata Controller. If the system you want to be the Primary Metadata Controller is not currently controlling the volumes, return control to the intended Primary Metadata Controller Upgrade all client systems to 10.3.9…
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Xsan: Unresponsive Xsan Admin
There are times with Xsan when the admin utility sits unresponsive (the pinwheel at the bottom of the screen spins annoyingly to no end). When the Admin tool gets unresponsive you are typically staring down the barrel of some kind of naming issue. In these cases I almost universally have DNS administrators tell me that everything is fine without first bothering to actually look at the records for the hosts on the SAN. The easy way to verify this hypothesis is to build a custom hosts file (/etc/hosts). This bypasses the DNS resolver and if everything loads up correctly then you do indeed have a DNS/host naming issue.
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Just Some Notes On Xsan Planning
Planning an Xsan is perhaps the most complicated part of any deployment. First, start with one of two objectives, speed or size (or both). How big does the SAN need to be and what speeds does the SAN (aggregate speed of all clients) need to be able sustain? That becomes the primary design consideration. Beyond that, you’ll also want to plan how it will get backed up and when, the makeup of the clients (Mac, PC, Linux), how permissions will get handled for new files written to the SAN, etc. Metadata Xsan needs an out-of-band metadata network. This network is used to transfer information, or metadata on files being written…
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Xsan: Metadata
It occurred to me that I’ve been talking about Xsan for awhile but I didn’t start with the key element of what makes an Xsan an Xsan. It’s metadata. Metadata is typically the extended attributes of a file (eg – with iTunes it is the artist, keywords, how much you like or dislike the song, etc). With Xsan metadata is information about where all of your files are stored, or if they’re broken into many parts (and most are) then it’s the information needed to find those parts across the various LUNs, Storage Pools, Blocks and Stripes that they sit on and how to then put those parts back together. This…
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Practical ILM
I originally posted this at http://www.318.com/TechJournal The amount of data used by Small Businesses is on target to rise 30% to 35% in 2006. Sarbanes-Oxley, HIPPA and SEC Rule 17a-4 have introduced new regulations on the length of time data must be kept and in what format. Not only must data be kept, it must be backed up and secured. These factors have the cost of data storage for the Small Business increasing exponentially. Corporations valued at more than 75 million dollars are generating 1.6 billion gigabytes of data per year. Small and medium sized companies can reap the benefits of developments being made with larger corporations. Different methods and…
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Xsan: umask and Default Permissions
I originally posted this at http://www.318.com/TechJournal By default the global permissions for new files written into an Xsan volume are 644 (rw-r–r–). This can result in a permissions problem where one user can read another user’s posted items, but not make changes to it. This can be resolved by changing the default umask value for groups. It’s a simple command line: sudo defaults write -g NSUmask 23 In this case, the 23 is a decimal equivalent of “rw-â€. So the result of running this command line is that files posted to the shared volume will have 664 permissions (rw-rw-r–), allowing other users in the group to modify the files. Note…
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Preventing Firewall Issues with Xsan
I originally posted this at http://www.318.com/TechJournal Introduction Xsan requires a dedicated ethernet network in the supported architecture by Apple. For systems that are obtaining directory information or need to be wired into the corporate network of many organizations this can cause issues. Namely that Xsan will attempt to use the corporate network for connectivity with clients. We see this in many configurations and it can cause dropped packets, unmountable volumes and other intermittent issues. One way to fix this for metadata controllers is to choose the network adapter that you would like to use on the metadata network in Server Admin. This can be done by: Open Xsan Admin Click…
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Xsan Presentation from Black Hat
My Xsan presentation from Black Hat 2006, in Las Vegas, NV: bh-us-06-edge
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Xsan: cvadmin
Xsan Admin is a little wonky sometimes. This isn’t to say there are bugs, just that sometimes given the environmental factors it can be slow to respond. But once your SAN is up and running you can pretty much do all the admin tasks you’ll ever need using cvadmin rather than Xsan Admin. cvadmin is an interactive command line environment and will always need to be run with escalated priveleges (er, sudo). So use the following command to see which Metadata Controllers are available and to see which is your primary per volume: sudo cvadmin man Now you can use sudo cvadmin and from within the interactive cvadmin command…
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Xsan Admin slow to respond?
It’s probably a naming or DNS issue… As a temp test, create a hosts file with all the systems in it. If it works fine then try and isolate that DNS issue…