mirror-copy not working

[Michael Neumann]

On Mon, Jan 15, 2018 at 10:28:18AM +0100, Konrad wrote:
> Dear reader, 
> 
> I???m running into a problem setting up hammer mirroring that I don???t understand. I???ve set up two filesystems, master on one machine and slave on another. To my understanding, that setup looks good: 
> 
> zoii# hammer pfs-status /pfs/hg
> /pfs/hg PFS#1 {
>    sync-beg-tid=0x0000000000000001
>    sync-end-tid=0x000000010e046740
>    shared-uuid=7229d076-f45c-11e7-b4cb-010c29f043b1
>    unique-uuid=7229d083-f45c-11e7-b4cb-010c29f043b1
>    label=""
>    prune-min=00:00:00
>    operating as a MASTER
>    snapshots directory defaults to /var/hammer/<pfs>
> }
> 
> # hammer pfs-status zoii-hg
> zoii-hg	PFS#8 {
>    sync-beg-tid=0x0000000000000001
>    sync-end-tid=0x0000000000000001
>    shared-uuid=7229d076-f45c-11e7-b4cb-010c29f043b1
>    unique-uuid=4737dd98-f9d2-11e7-b3fd-3da82a9fd340
>    label=""
>    prune-min=00:00:00
>    operating as a SLAVE
>    snapshots directory defaults to /var/hammer/<pfs>
> }
> 
> ssh communications work well, I???ve also checked that. But:
> 
> zoii# hammer mirror-copy /pfs/hg root at 192.168.11.11:/pfs/zoii-hg
> Prescan to break up bulk transfer
> Prescan 2 chunks, total 4646 MBytes (4818387768, 53692688)
> hammer: Mirror-write /pfs/zoii-hg fatal error 22
> 
> The only other thing I can find is (on the machine with the slave filesystem)
> 
> Jan 15 09:59:27 df1 kernel: hammer_create_at_cursor: CRC DATA @ 900000da3c8d16f0/128 MISMATCH ON PIPE

You are doing nothing wrong here! Hm, looks to me as if data corruption
is happening while the data is being transfered from one machine to the
other. Does this happen every time you run mirror-copy? You could test
to run mirror-copy locally first (hammer mirror-copy /pfs/hg
/pfs/test-hg), but in case your filesystem is pretty large this is
something you might not want to do.

Regards,

  Michael