I migrated all of our ~60 VMs (1.2TB) from our old FC SAN to our new array and experience very slow VDR backups.
old array: 10x300gb 15k 3.5inch in RAID10 configuration, datastore blocksize 2mb
new array: 12x600gb 10k 2.5inch also in RAID10 configuration, datastore blocksize 1mb
both are connected via FC 8G
Migration was done via Storage vMotion, took quite some time because of the different blocksize values.
VDR's dedupe store is an 800GB RDM from another FC san with 4Gbit/s
Before the migration backups took a maximum of 2 hours to finish, now i'm looking at 8hours +.
Could it be because of the new smaller blocksize ? I thought maybe it levels out after a few days, but after 5 days I still see no difference.
According to the VDR logs, SCSI-Hot Add is being used, and also CBT/CTK is active.
The retention policy keeps up to 8week old backups.
Will I be better off creating a fresh LUN for VDR so it wouldn't have to check my old backups which were from the old 2mb datastore?