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ahmad_faraz
2 Bronze

Mirror positions of standard device

Where exactly are the mirror position M1 M2 M3 M4 located for a standard device ..Say  a device is raid10 or raid-5 are the no of mirrors and mirror positions

same for both .

Does the mirror position occupy disk space .Can these mirror position be same as Raid 10 .

.Can some one please explain this as i am quite lost in this ..

Regards

Faraz

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2 Replies
Quincy561
4 Tellurium

Re: Mirror positions of standard device

Mirror positions are just logical placeholders for device mirrors.  These can be local mirrors for RAID1, or in DMX RAID5 or they can be true BCVs (not clones), or RDF mirrors.  The physical mirror location will depend on the type.  If it is a local mirror, that will be on a disk somewhere in the system.  If a RDF mirror, that will be in a second array somewhere else, and in that array, it may have several mirror positions taken up as well.

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Mana3
1 Copper

Re: Mirror positions of standard device

 

Each Symmetrix logical volume is allowed up to 4 mirrors irrespective of the configuration type. Prior to Enginuity 5874, local mirrors and parity RAID mirrors would occupy a second mirror position. This limited the number of remote mirrors and TimeFinder/Mirror BCVs these volumes could be joined to.

Starting with Enginuity 5874, RAID virtual architecture (RVA) virtualizes mirror positions. Regardless of RAID type, all volumes occupy one local mirror position. This means that backend management of RAID groups is hidden from rest of Enginuity. Remote mirrors still occupy a mirror position but local mirrors no longer occupy a mirror position irrespective of their protection type.

Also, TimeFinder/Mirror was discontinued and replaced with TimeFinder/Clone starting 5874. Thus the 4 mirror limit is no longer a limiting factor.

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