Network manager broken after uninstall indicator network

osnaile Leave a comment

After I test indicator network, i don’t like it. So uninstall indicator network by Synaptic Package Manager. But network manager can’t work after uninstall indicator. network manager alter “networking disable”.
I search some way to fix it, lots of ways are not good.

Here is my way to fix it:
Edit /etc/NetworkManager/nm-system-settings.conf
change “managed=false” to “managed=true”
And uninstall “connman” in Synaptic Package Manager.

It works after reboot.

Ref: http://www.omgubuntu.co.uk/2010/05/help-test-ubuntu-10-10s-proposed-network-indicator-applet-ppa/

Get the size of data table in SQL Server

osnaile Leave a comment

Get the row count and size of data table is very important in SQL Server.
These infomation about data table can select by stored procedure “sp_spaceused”.

usage of “sp_spaceused”: http://msdn.microsoft.com/en-us/library/ms188776.aspx

To get all table’s infomation by the following SQL:

CREATE TABLE #t(name VARCHAR(255), ROWS BIGINT, reserved VARCHAR(20), DATA VARCHAR(20), index_size VARCHAR(20), unused VARCHAR(20))
EXEC sp_MSforeachtable "insert into #t exec sp_spaceused '?'" 
SELECT * FROM #t ORDER BY name
DROP TABLE #t

based: http://www.cnblogs.com/drc/archive/2007/11/29/977189.html

Count file in Linux

osnaile Leave a comment

Count file in a directory:

ls -l |grep "^-"|wc -l

Count file in a directory, include subdirectories:

ls -lR|grep "^-"|wc -l

Count subdirectory in a directory:

ls -l|grep "^d"|wc -l

Count subdirectory in a directory, include subdirectories:

ls -lR|grep "^d"|wc -l

Some experience about ZFS

osnaile Leave a comment

ZFS is a good file system, it can manage lots of disks.
I have three 1G harddisks when I use ZFS beginning. In accordance with my experience, raid 5 is my first choice. Raid 5 is called raidz in ZFS. Suppose my pool is named nas, I created this pool by the following command:

zpool create nas raidz c9d0t0 c9d1t0 c9t2d0

After create pool, check the pool statu:

$ zpool status -v nas
  pool: nas
 state: ONLINE
 scrub: none requested
config:
 
        NAME        STATE     READ WRITE CKSUM
        nas         ONLINE       0     0     0
          raidz1-0  ONLINE       0     0     0
            c9t0d0  ONLINE       0     0     0
            c9t1d0  ONLINE       0     0     0
            c9t2d0  ONLINE       0     0     0
 
errors: No known data errors

It’s time to consider to expand the capacity when this pool is full.

After I get a 2G harddisk, I have two choice:
1.replace a old disk in the pool;
2.Add the new disk into the pool.

I wouldn’t waste a disk, so I choose the second.

I checked some document, raidz don’t support add a new disk to raidz. If I use the following command:

zpool add nas c9t3d0

the new disk will add to the pool by raid 0. It isn’t what I want.

So, the raid 1 + 0 is recommended in the future.
Create raid1 pool first. Create another raid1 and add the new mirror to the old pool by raid0, when it need to add new disks.