Create the NFS share file system in the N8000, after the Linux client mounting, execute “dd” command but it hang:
1. In the N8000, create the NFS share and the NFS server status is normal:
gensys.NFS> share show
/vx/fs222 * (rw,sync,secure,no_root_squash,wdelay)
gensys.NFS> server status
NFS Status on gensys_01 : ONLINE
NFS Status on gensys_02 : ONLINE
2. Create the share catalog in the client, and mount to the “N8000 /vx/fs222” file system.
DS-client7:~ # mkdir fs222 # create the share catalog “fs222”
DS-client7:~ # mount -t nfs 22.214.171.124:/vx/fs222 /fs222 # mount via the default parameters
DS-client7:~ # mount # view the mounting status
126.96.36.199:/vx/fs222 on /fs222 type nfs (rw,addr=188.8.131.52) # display the successful mounted share catalog
3. Execute the “dd” command:
DS-client7:~ # cd /fs222/
DS-client7:/fs222 # dd if=/dev/zero of=50g.data bs=1M count=50000
4. Execute the “ls” command:
DS-client7:/ # cd fs222/
DS-client7:/fs222 #ls command has been “hang”, and it has been hang for about 2 minutes
5. View the logs:
DS-client7:~ # echo t>/proc/sysrq-trigger # export the information of the thread status
DS-client7:~ # tailf /var/log/messages
May 17 12:48:32 DS-client7 kernel: [351714.363671] Call Trace:
vt_event_wait 0x9f/0x120 # after the “io” event has completed, the “dd” command has occupied the lots of system resource for a long time, and causes the “ls” command can’t respond.
vt_waitactive 0x2d/0x60 # wait to active the io event.
vfs_ioctl 0x2f/0xb0 # call the “vfs io” request.
Modify the priority of the “dd” command in the operating system, and make a equilibrium mechanism of the operating system resources, so the system can’t make any single service occupying the system resource and then causes the other services can’t implement.
Build the NFS server via the standard Linux and compare with the clients of two different operating systems, execute the “dd” command in the share catalog, and then execute the “ls” command, it has been hang in the two operating systems. Execute the “cp” command to copy the file in the share catalog, and then execute the “ls” command again, hence, it can’t hang any longer.
The detail information is not known.