Migrating from 6.0.14 to 8.0.6

I am trying to migrate my zimbra server from 6.0.14 to 8.0.6 i have 6981 accounts on server and that took me almost 48h to backup. Now i am trying to restore on new server ( to take the backup i mounted a folder on the new server and backuped there, and now i am using the same path on the new server to migrate) I set the owner and group for folders and files to zimbra and started the process to restore, but it takes too long on the first task on wizard "Check Import Path" is that normal with almost 7000 accounts ? or maybe is something wrong ?

zxsuite backup getBackupInfo backup_path /mnt/hdd/

exists                                              true
readable                                            true
valid                                               true
empty                                               false
lockok                                              true
writable                                            true
caseSensitive                                       true
backupStat
fullScan
firstZeXtrasBuild                                           2cc8a9aff3fa88d29498d7fc3b3a02f20da8627a
firstZeXtrasVersion                                         1.8.13
firstZimbraVersion                                          6.0.14
backupPath                                                  /mnt/hdd
lastSuccessful                                              Success
firstScan                                                   2014-03-08 15:46:16 EET
lastScan                                                    2014-03-08 15:46:16 EET
lastZeXtrasBuild                                            2cc8a9aff3fa88d29498d7fc3b3a02f20da8627a
lastZeXtrasVersion                                          1.8.13
lastZimbraVersion                                           6.0.14
numTotalAccounts                                            6981
numActiveBackuppedAccounts                                  6981
numZimbraItems                                              3520045
numBackuppedItems                                           3520045
numItemsPerSecond                                           0
smartScan
firstZeXtrasBuild                                           2cc8a9aff3fa88d29498d7fc3b3a02f20da8627a
firstZeXtrasVersion                                         1.8.13
firstZimbraVersion                                          8.0.6
dataPath                                            /mnt/hdd/

I Forgot to mention that total space took for backup is 267GB