Is it possible to split concatenated LUNs?

Question

We have SUN attached to Solaris server running Oracle database. We were running out of space on one of LUNs so we decided to expand it. We concatenated new LUN to the old one but after that we learned that Solaris will not see new space anyway (without playing tricky games with disk geometry information). Server is 24/7 with live data on it so we cannot afford any downtime. Because second LUN is not visible and accessible from Solaris than our new idea is to remove concatenation and attach second LUN as new drive.

The question is: is it possible to remove concatenated second LUN without jeopardize data on old LUN?

Thank you.

dynamox · Accepted Answer

i am afraid you are out of luck because its not possible, your best bet would be to make a clone of the concatenated lun and attempt your geometry option at least you could attempt to get that space ..worth case scenario you would roll back from your clone.

dynamox · Answer

yeah, that probably would be the safest thing to do considering importance of the data. If you have the space maybe you can clone it to another lun and once the new lun presented.. copy from clone to the new LUN with cpio on cp ..hopefully that would be faster than tape.

dynamox · Answer

how much space have you potentialy lost ...are you goinh to attemp playing with disk geometry ?

dynamox · Answer

do you use veritas ? if yes then you can actually do it online. You could build another lun, extend it into a volume group ..then mirror logical volumes from that concatenated lun to the new one. once all logical volimes are mirror ..split the mirror and reduce that concatenated lun out. At that point you could remove it from the OS and destoy it. All this can be done online if you are using Veritas.

Mirek2 · Answer

No, we will schedule downtime, backup all data, destroy entire MetaLUN and create new big LUN. That's probably the best approach with Solaris servers.

Mirek2 · Answer

Unfortunately for me we are not using Veritas but Sun's DiskSuite.LUNs were concatenated under Navisphere so it's not possible just break MetaLUN without destroying it, right?

Mirek2 · Answer

I made it even 22 points. Thanks.

dynamox · Answer

nope

Mirek2 · Answer

Thank you Sir! That was very quick response. You just earned next 10 points

Mirek2 · Answer

That's a good idea. We have a space on SAN so we can think about cloning to speed up entire process. Another good reply.Thank you very much for your help.

CLARiiON

Is it possible to split concatenated LUNs?

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