xsanity
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Q: Help! Is our Xsan Setup Correctly?
Hello all,
I've been tasked to trouble shoot our current Xsan environment, which has trouble with high latency in the 3K ms which breaks read/write access for users on occasion. The only way to fix this thus far is to unmount the volume and restart the server.
What I would like to know is if we have our Xsan system setup correctly. We have two sets of arrays. Array 1 = 1 x Vtrak E Calls with 2 x J Class expansions attached and Array 2 = 1 x Vtrak E Calls with 2 x J Class expansions attached, which is an identical setup.
The two separate arrays are not joined together with any SAS cables. They all converge into the same fiber switch tough. We have metadata mirrored on the first two drives of the first array and two dedicated Metadata controllers. The two arrays are logically connected via software, the two arrays are seen as one large production volume.
Is this setup up correctly? Should we have Metadata on the second array too, like a "multi-san" setup? Each shelf of 16 drives is setup in halfs. The first two column of 8 drives as raid 5 and the second 2 column of 8 drives as raid 5 also and so on. Should all 16 drives have been setup as one LUN?
Our MDC's are on closed/separate network on a dedicated switch using separte interfaces on the Xserve's. The high latency is seen via cli in cvadmin running the 'latency-test' command. Based on our setup shouldn't the two separate arrays be attached via SAS cable so they act as one unit or does it not matter considering there are two Vtrac E subsystems required to do this, which is more expensive. I'm still learning, so I'm asking a lot of why questions:)
Just curious as to why the person setup the SAN this way, maybe there are advantages with two physically separate arrays connected via fiber switch but acting as one large volume? Would this cause latency?
I have limited experience with Xsan but have done lots of research to be come more educated about Xsan deployments and would like to know the answers to these questions, so I can plan to rebuild the system when time and schedule permits.
Thanks in advance for any help.
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Here is a grab of our volume information.
[IMG]http://img545.imageshack.us/img545/803/xsanvolumeinfo.jpg[/IMG]
I've been tasked to trouble shoot our current Xsan environment, which has trouble with high latency in the 3K ms which breaks read/write access for users on occasion. The only way to fix this thus far is to unmount the volume and restart the server.
What I would like to know is if we have our Xsan system setup correctly. We have two sets of arrays. Array 1 = 1 x Vtrak E Calls with 2 x J Class expansions attached and Array 2 = 1 x Vtrak E Calls with 2 x J Class expansions attached, which is an identical setup.
The two separate arrays are not joined together with any SAS cables. They all converge into the same fiber switch tough. We have metadata mirrored on the first two drives of the first array and two dedicated Metadata controllers. The two arrays are logically connected via software, the two arrays are seen as one large production volume.
Is this setup up correctly? Should we have Metadata on the second array too, like a "multi-san" setup? Each shelf of 16 drives is setup in halfs. The first two column of 8 drives as raid 5 and the second 2 column of 8 drives as raid 5 also and so on. Should all 16 drives have been setup as one LUN?
Our MDC's are on closed/separate network on a dedicated switch using separte interfaces on the Xserve's. The high latency is seen via cli in cvadmin running the 'latency-test' command. Based on our setup shouldn't the two separate arrays be attached via SAS cable so they act as one unit or does it not matter considering there are two Vtrac E subsystems required to do this, which is more expensive. I'm still learning, so I'm asking a lot of why questions:)
Just curious as to why the person setup the SAN this way, maybe there are advantages with two physically separate arrays connected via fiber switch but acting as one large volume? Would this cause latency?
I have limited experience with Xsan but have done lots of research to be come more educated about Xsan deployments and would like to know the answers to these questions, so I can plan to rebuild the system when time and schedule permits.
Thanks in advance for any help.
Back to top
View user's profile Send private message
Here is a grab of our volume information.
[IMG]http://img545.imageshack.us/img545/803/xsanvolumeinfo.jpg[/IMG]
Mac OS X (10.5.8)
Posted on Sep 24, 2010 9:14 AM
![[IMG]http://img545.imageshack.us/img545/803/xsanvolumeinfo.jpg[/IMG]](http://img545.imageshack.us/i/xsanvolumeinfo.jpg/){kind=link}