VM backup Failed

Hi i amtrying to run a backup of a virtual machine, but i am receiving this error.

/20/2015 6:21:16 PM - Info nbjm(pid=8120) starting backup job (jobid=92040) for client SUBFPS8.pttphils.com, policy VMBackup_Critical_Servers, schedule Daily_Full_Backup 

4/20/2015 6:21:17 PM - estimated 0 Kbytes needed

4/20/2015 6:21:17 PM - Info nbjm(pid=8120) started backup (backupid=SUBFPS8.pttphils.com_1429525276) job for client SUBFPS8.pttphils.com, policy VMBackup_Critical_Servers, schedule Daily_Full_Backup on storage unit subbacw_msdp_storage_unit

4/20/2015 6:21:17 PM - started process bpbrm (8484)

4/20/2015 6:21:17 PM - Info bpbrm(pid=8484) SUBFPS8.pttphils.com is the host to backup data from    

4/20/2015 6:21:17 PM - Info bpbrm(pid=8484) reading file list from client       

4/20/2015 6:21:17 PM - connecting

4/20/2015 6:21:18 PM - Info bpbrm(pid=8484) starting bpbkar32 on client        

4/20/2015 6:21:18 PM - Info bpbkar32(pid=13284) Backup started          

4/20/2015 6:21:18 PM - connected; connect time: 00:00:01

4/20/2015 6:21:19 PM - Info bpbkar32(pid=13284) CONTINUE BACKUP received.         

4/20/2015 6:21:19 PM - Info bptm(pid=15040) start           

4/20/2015 6:21:19 PM - Info bptm(pid=15040) using 262144 data buffer size       

4/20/2015 6:21:19 PM - Info bptm(pid=15040) setting receive network buffer to 1049600 bytes     

4/20/2015 6:21:19 PM - Info bptm(pid=15040) using 30 data buffers        

4/20/2015 6:21:26 PM - Info bptm(pid=15040) start backup          

4/20/2015 6:21:50 PM - begin writing

4/20/2015 6:25:15 PM - Info bpbkar32(pid=13284) INF - Transport Type = nbd      

4/20/2015 6:31:23 PM - Info bptm(pid=15040) waited for full buffer 2620 times, delayed 22795 times   

4/20/2015 6:31:23 PM - Info bpbkar32(pid=13284) bpbkar waited 73 times for empty buffer, delayed 4084 times.  

4/20/2015 6:31:37 PM - Info subbacw.pttphils.com(pid=15040) StorageServer=PureDisk:subbacw.pttphils.com; Report=PDDO Stats for (subbacw.pttphils.com): scanned: 2221417 KB, CR sent: 64738 KB, CR sent over FC: 0 KB, dedup: 97.1%

4/20/2015 6:31:39 PM - Error bpbrm(pid=8484) could not send server status message      

4/20/2015 6:31:39 PM - Critical bpbrm(pid=8484) unexpected termination of client SUBFPS8.pttphils.com       

4/20/2015 6:31:39 PM - Info bpbkar32(pid=0) done. status: 11: system call failed      

4/20/2015 6:31:39 PM - end writing; write time: 00:09:49

system call failed(11)

Help pls..