starport 5.5 Mirror Fast initialization

haahof · Sun Mar 28, 2010 3:30 pm

I am using starport 5.5 to mirror a local image and a remote ISCSI(starwind) target. I am mounting the mirrored volume as the backup device for win2k8 environment. Both the local and remote images are raw and have never been mounted. My question is this: Is there a fast way to intialize the empty mirror within starport?

The first client is set this up for I tried to "Clear mirrors"(500GB image). After the local image cleared and I realized how long it would take to clear the remote ISCSI image I stopped the process and recreated the mirror selecting the "Synchromize mirrors data" option on the initialization screen. This ran pretty quickly and I was able to mount the drive and begin using it for backup.

The second client I am trying to do this with(750GB) I cannot seem to get the mirror to initialize quickly. I tried repeating the steps I used with the first client with no luck. At this rate it will take ~2 weeks to fully sync the empty image.

I have no idea why it worked so well with the first client but I am happy with the results. Please let me know if you have any ideas.

Thanks,

-christopher

haahof · Mon Mar 29, 2010 2:59 am

For the time being I have converted both the local and remote image from basic to dynamic disks so the OS could mirror them quickly.. This isn't ideal for a variety of reasons. Again, I am not sure how I got the 500GB raid one device to initialize so quickly.. but it works great. Backups run to both, and restores are quick while the active mirror is the local image. Swtching passive and active works as intended.

If anyone knows how to quickly initialize fresh(raw) raid-1 devicies through the latest version of startport, please let me know.

-christopher

Constantin (staff) · Mon Mar 29, 2010 4:43 pm

Synchronization takes data from one node, while clear operation fills`em with zeroes.

haahof · Mon Mar 29, 2010 5:45 pm

If both images are raw.. empty.. etc.. shouldn't the initialization be pretty quick? There is not data to sync at that point.

Mon Mar 29, 2010 9:31 pm

Physically filling up containers with zeros also takes time...

haahof wrote:If both images are raw.. empty.. etc.. shouldn't the initialization be pretty quick? There is not data to sync at that point.

haahof · Mon Mar 29, 2010 10:07 pm

For the "fill with zero" option I understand will take time, but the sync option, where the primary or active mirror is a new, empty image I would think could sync alot quicker. That is my question, is there a way to quickly sync and initialize two new raw images?

Mon Mar 29, 2010 11:45 pm

Yes, but when you allocate an image it's trashed with a garbage (content originally stored on the disk). To have RAID set created properly we need to make sure we have the containers filled with zeros (calculate CRCs for future fast syncs, keep track of writes etc). That's why *initially* we still need to write to ALL of the sectors both mirrors have. Takes time

(

haahof wrote:For the "fill with zero" option I understand will take time, but the sync option, where the primary or active mirror is a new, empty image I would think could sync alot quicker. That is my question, is there a way to quickly sync and initialize two new raw images?