Slaine's questions

有一个服务器通过 targetcli 分发 lvm 部分，比如块磁盘。在 lvextend 的帮助下扩展，lv_pub 部分从 300 GB 增加到 350 GB。

# pvs
  PV         VG             Fmt  Attr PSize   PFree  
  /dev/md126 centos_tgt4 lvm2 a--  465.13g 160.00m
  /dev/sda1  vg_tgt4     lvm2 a--   16.37t   3.22t

# vgs
  VG             #PV #LV #SN Attr   VSize   VFree  
  centos_tgt4   1   4   0 wz--n- 465.13g 160.00m
  vg_tgt4       1   5   0 wz--n-  16.37t   3.22t

# lvs
  LV             VG             Attr       LSize   Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert
  home           centos_tgt4 -wi-ao---- 429.06g                                                    
  root           centos_tgt4 -wi-ao----   9.96g                                                    
  swap           centos_tgt4 -wi-ao----  15.96g                                                    
  var            centos_tgt4 -wi-ao----  10.00g                                                    
  lv_cub         vg_tgt4     -wi-ao----   1.00t                                                    
  lv_group       vg_tgt4     -wi-ao----   4.50t                                                    
  lv_home        vg_tgt4     -wi-ao----   1.50t                                                    
  lv_doc         vg_tgt4     -wi-ao----   5.81t                                                    
  lv_pub         vg_tgt4     -wi-ao---- 350.00g

#targetcli
targetcli shell version 2.1.fb41
Copyright 2011-2013 by Datera, Inc and others.
For help on commands, type 'help'.

/> ls
o- / ......................................................................................................................... [...]
  o- backstores .............................................................................................................. [...]
  | o- block .................................................................................................. [Storage Objects: 5]
  | | o- cub ................................................................... [/dev/vg_tgt4/lv_cub (1.0TiB) write-thru activated]
  | | o- group ........................................................ [/dev/mapper/vg_tgt4-lv_group (4.5TiB) write-thru activated]
  | | o- home .......................................................... [/dev/mapper/vg_tgt4-lv_home (1.5TiB) write-thru activated]
  | | o- doc ............................................................ [/dev/mapper/vg_tgt4-lv_doc (5.8TiB) write-thru activated]
  | | o- pub ................................................................. [/dev/vg_tgt4/lv_pub (350.0GiB) write-thru activated]

在客户端上看不到空间增加了：

# pvs
  PV         VG     Fmt  Attr PSize    PFree 
  /dev/sdc   vg_cub lvm2 a--  1024.00g 24.00g
  /dev/sde   vg_pub lvm2 a--   300.00g 10.00g

fdisk，看到磁盘被放大了，但是没有看到分区：

# fdisk /dev/sde
Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel
Building a new DOS disklabel with disk identifier 0xa81facb2.
Changes will remain in memory only, until you decide to write them.
After that, of course, the previous content won't be recoverable.

Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite)

The device presents a logical sector size that is smaller than
the physical sector size. Aligning to a physical sector (or optimal
I/O) size boundary is recommended, or performance may be impacted.

WARNING: DOS-compatible mode is deprecated. It's strongly recommended to
     switch off the mode (command 'c') and change display units to
     sectors (command 'u').

Command (m for help): p

Disk /dev/sde: 375.8 GB, 375809638400 bytes
255 heads, 63 sectors/track, 45689 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 262144 bytes
Disk identifier: 0xa81facb2

   Device Boot      Start         End      Blocks   Id  System

Command (m for help): ^C

大批：

float v[] = {
0.5, 0,5, 0.0,
1.0, 0.5, 0.0,
0.5, 0.5, 0.0,
-0.5, 0.5, 0.0,
1.0, 0.5, 0.0,
0.5, 0.5, 1.0,
0.5, 0.5, 1.0}

您需要使用从零开始的整数索引数组中的每组三个数字，并将索引写入另一个数组，即 前三个数字将始终为 0。

例如：0.5、0.5、0.0 - 索引零，

1.0, 0.5, 0.0 - 索引 1,

0.5, 0.5, 0.0 - 零索引（因为组已经满足），

-0.5, 0.5, 0.0 - 索引 2,

1.0, 0.5, 0.0 - 索引 1,

0.5、0.5、1.0 - 索引 3 等

结果，新数组应如下所示： int v2[] = {0, 1, 0, 2, 1, 3, 3}

Centos7，鱿鱼 3.5。

Squid 在 /etc/squid/proxy.keytab 中找不到 keytab 文件。cache.log 有这个文本：

negotiate_kerberos_auth.cc(487): pid=10259 :2018/07/10 16:48:02| negotiate_kerberos_auth: INFO: Starting version 3.0.4sq
2018/07/10 16:48:02 kid1| Starting new negotiateauthenticator helpers...
2018/07/10 16:48:02 kid1| helperOpenServers: Starting 1/10 'negotiate_kerberos_auth' processes
negotiate_kerberos_auth.cc(546): pid=10258 :2018/07/10 16:48:02| negotiate_kerberos_auth: INFO: Setting keytab to FILE:/etc/krb5.keytab
negotiate_kerberos_auth.cc(75): pid=10258 :2018/07/10 16:48:02| negotiate_kerberos_auth: ERROR: krb5_kt_start_seq_get failed: Key table file '/etc/krb5.keytab' not found
2018/07/10 16:48:02| negotiate_kerberos_auth: ERROR: krb5_kt_start_seq_get: Key table file '/etc/krb5.keytab' not found
negotiate_kerberos_auth.cc(75): pid=10258 :2018/07/10 16:48:02| negotiate_kerberos_auth: ERROR: krb5_read_keytab failed: Key table file '/etc/krb5.keytab' not found
2018/07/10 16:48:02| negotiate_kerberos_auth: ERROR: krb5_read_keytab: Key table file '/etc/krb5.keytab' not found
negotiate_kerberos_auth.cc(556): pid=10258 :2018/07/10 16:48:02| negotiate_kerberos_auth: ERROR: Reading keytab FILE:/etc/krb5.keytab into list failed

IE。如何告诉 Squid 在那里寻找什么文件？当然，你可以在 /etc 中放一个文件，比如 krb5.keytab，但还是这样吗？谢谢你。

如何使用指向对象的指针打印指针 p 的值？

#include <iostream>
class Test {
    public:
        int a = 1;
        int *p = &a;
};
int main(){
    using namespace std;
    Test* obj = new Test;
    cout << obj->*p << endl;
    return 0;
}

qemu-kvm-1.5.3-141.el7_4.4.x86_64

无法创建快照：

virsh snapshot-create-as --domain vm1 snapshot --disk-only --atomic --quiesce --no-metadata

错误：

error: Операция не поддерживается: Этот QEMU не поддерживает создание снимка работающего диска

来宾已安装并运行 qemu-ga。

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Statement;


public class vacuum {
    public static void connect(String str) {
        Connection conn = null;
        Statement stmt = null;
        try {
            String url = "jdbc:sqlite:/data/" + str;
            conn = DriverManager.getConnection(url);
            stmt = conn.createStatement();
            stmt.executeUpdate("VACUUM");

            System.out.println(str + "ok.");

        } catch (SQLException e) {
            System.out.println(e.getMessage());
        } finally {
            try {
                if (conn != null) {
                    conn.close();
                }
            } catch (SQLException ex) {
                System.out.println(ex.getMessage());
            }
        }
    }

    public static void main(String[] args) {
        String str = "db1.lgd";
        connect(str);
    }
}

有几个 Sqlite 数据库需要清理。我想在几个平行流中对所有基地进行真空处理。那些。将数组中的碱基列表传递给 connect 方法，并在单独的线程中运行该方法本身。以上是为一个基地做真空的工作代码。提示，它要执行吗？