Hello,
I wonder what transferrate I could expect for snapmirror volumes (an/or qtrees) between 2 FAS270 directly connected with Gigabit Ethernet.
Could you detail more about your mirroring setup ...
Volume or Qtree snapmirror?
What is the snapmirror schedule?
Synch or Async?
What sort of volume setup? (traditional, flex)?
Are the disks identical at both ends? What type and quantity of disks?
are you following the recommendations in the snapmirror best practices guide?
What sort of cpu utilization are you seeing on the source and destination?
I have a maildir setup with slightly more files than yours and about 100GB more data. I'm Volume snapmirroring over 100Mbps ethernet, and It takes ~10-15 Minutes to mirror the deltas, which are about 6-8 GB. I'm running 7.0.5. If memory serves me correctly, I upgraded because I saw some ugly Snapmirror bugs associated with 7.0.4 as a preventive measure.
Otherwise snapmirror works at the block level for transfers, file sizes shouldn't matter.
Regards, Max
We use one filer as NFS backing store for our Mailsystem (Communigate Pro) with mdir mailbox format, so we have many small files here.
I see abnormal high lags with really moderate sizes of the transferred data.
For instance we need about 20 to 40 minutes to transfer 100 to 600 MBytes!
The filesystems a 50% filled 250 GByte Volume/qtree with 10.3 million files (with 7 mio free inodes).
so the average filesize is about 12KByte.
We use Ontap 7.0.4 here and will upgrade to 7.0.5 next week. But I don't really have much hope that this will change the problem.
Could anybody give me some data about his/her transfer rates? I really can't believe, that this slow transfers are normal.
An repeatedly snapmirror status command on the filer shows this:
at first the transfer startet and transferred about 68 MByte in 80 seconds. after that it paused for 15 minutes (output constantly "transferring 68MB done"). from minute 16 to 26 it says "transferring inodes". in these 11 minutes it transferred 225.000 inodes. after that it transfers data again. in minute 28 it has transferred 550 MBytes. after that one minute pause and then the status is idle.
Has netapp/snapmirror a big problem with small files? I don't want to switch to mailbox format because I like the advantages of mdir (single copy mailstore, easier backup?)
Thanks for any hints, thomas