Forum Discussion

tanislavm's avatar
tanislavm
Level 6
11 years ago

dg import

Hi, I like to verify the steps how an dg is imported. vxdg import dg,the vxio will issue an query on all HBA ports to find all the disks who have that dg name written on private area.right?In this que...
business continuity
Solaris
Storage Foundation
  • Gaurav_S's avatar
    Gaurav_S
    11 years ago

    Answers

    vxdg import dg,the vxio will issue an query on all HBA ports to find all the disks who have that dg name written on private area.right?In this query is involved vxdisk scandisk?

    >> Yes, vxio will make the IOs on SCSI & find the disks & will update vxconfigd. vxconfigd knows about all the disks & their private region. To my understanding this query doesn't involves "vxdisk scandisk"


    Also if an private area on an disk is corrupted,what is happening?The vxvm will solve it or I should to fix this issue?how?

    >> If private region is corrupted for some reason, vxvm won't try to solve problem itself, depending on what type of corruption it is, administrative intervention is required to recover it. It may be like, reinitializing the disk with same offsets, or rewriting the private region from old configuration backups etc.

    Then the volumes are started.Now the OS is able to see the disks.right?

    >> First OS should be able to see the disks, then VxVM will be able to see the disks. Once DG is imported, volumes in the dg will be started.


    If an volume has metadata corrupted how I fix it?with vxrecover,vxmend or vxcfgrestore?
    Also fsck?

    >> All are different problems. If you have issues on public region, you may need to think of backup restore. If the disk is having private region corruption, points which I mentioned in first answer would be applicable. vxrecover helps to recover private region config & bring back the volumes & plexes in enabled/active state.fsck may be required if public region had issues & filesystem inconsistency has occurred.


    Every volume has on it the filesystem and the data itself.right?

    >> Right


    If I have an mirror logical volume,then at any write I/O the vxvm modules will instruct the disk driver to write in parallel the data on both partitions.right?

    >> Right


    So when I perform mkfs -F vxvm then the disk driver will write in parallel the filesysyem on both partitions.When I use this vxassist to create an mirror,the disk driver will write in parallel on private area of both disks involved.right?

    >> Right, If you create a mirror using vxassist, there will be multiple subdisks involved, diskgroup configuration (private regions) of the disks will be updated with this information. As explained in your last post, there will be some disks in a diskgorup that contains the configuration copy. All the disks may not have the configuration copy enabled.

     

    G

Gaurav_S's avatar
Gaurav_S
Moderator
11 years ago

Answers

vxdg import dg,the vxio will issue an query on all HBA ports to find all the disks who have that dg name written on private area.right?In this query is involved vxdisk scandisk?

>> Yes, vxio will make the IOs on SCSI & find the disks & will update vxconfigd. vxconfigd knows about all the disks & their private region. To my understanding this query doesn't involves "vxdisk scandisk"


Also if an private area on an disk is corrupted,what is happening?The vxvm will solve it or I should to fix this issue?how?

>> If private region is corrupted for some reason, vxvm won't try to solve problem itself, depending on what type of corruption it is, administrative intervention is required to recover it. It may be like, reinitializing the disk with same offsets, or rewriting the private region from old configuration backups etc.

Then the volumes are started.Now the OS is able to see the disks.right?

>> First OS should be able to see the disks, then VxVM will be able to see the disks. Once DG is imported, volumes in the dg will be started.


If an volume has metadata corrupted how I fix it?with vxrecover,vxmend or vxcfgrestore?
Also fsck?

>> All are different problems. If you have issues on public region, you may need to think of backup restore. If the disk is having private region corruption, points which I mentioned in first answer would be applicable. vxrecover helps to recover private region config & bring back the volumes & plexes in enabled/active state.fsck may be required if public region had issues & filesystem inconsistency has occurred.


Every volume has on it the filesystem and the data itself.right?

>> Right


If I have an mirror logical volume,then at any write I/O the vxvm modules will instruct the disk driver to write in parallel the data on both partitions.right?

>> Right


So when I perform mkfs -F vxvm then the disk driver will write in parallel the filesysyem on both partitions.When I use this vxassist to create an mirror,the disk driver will write in parallel on private area of both disks involved.right?

>> Right, If you create a mirror using vxassist, there will be multiple subdisks involved, diskgroup configuration (private regions) of the disks will be updated with this information. As explained in your last post, there will be some disks in a diskgorup that contains the configuration copy. All the disks may not have the configuration copy enabled.

 

G