HCSF's questions

I am running squid 3.5.12 on Ubuntu.

I have the followings in /etc/squid/squid.conf

acl SSL_ports port 443
acl CONNECT method CONNECT
acl acl_allowed_ip src my.client.ip.address.com
http_access allow acl_allowed_ip
http_access allow localhost
http_access deny all
http_port 3128
coredump_dir /var/spool/squid
refresh_pattern ^ftp:           1440    20%     10080
refresh_pattern ^gopher:        1440    0%      1440
refresh_pattern -i (/cgi-bin/|\?) 0     0%      0
refresh_pattern (Release|Packages(.gz)*)$      0       20%     2880
refresh_pattern .               0       20%     4320

However, when I tried to telnet from the machine with my.client.ip.address.com, it just stuck there forever:

$ telnet my.squid.server.com 3128
Trying my.squid.server.com...
telnet: connect to address my.squid.server.com: Connection timed out

But if I telnet locally on my.squid.server.com, it works fine.

And I doubt checked that it is indeed the squid process listening to the port 3128:

# netstat -lp | grep 3128
tcp6       0      0 [::]:3128               [::]:*                  LISTEN      3142/(squid-1)  

firewalld is not running:

# systemctl status firewalld
● firewalld.service
   Loaded: not-found (Reason: No such file or directory)
   Active: inactive (dead)

Any idea how this can be fixed?

====================

Update #1: output of iptables -nvL

Chain INPUT (policy ACCEPT 79M packets, 55G bytes)
 pkts bytes target     prot opt in     out     source               destination         

Chain FORWARD (policy DROP 0 packets, 0 bytes)
 pkts bytes target     prot opt in     out     source               destination         
    0     0 DOCKER-USER  all  --  *      *       0.0.0.0/0            0.0.0.0/0           
    0     0 DOCKER-ISOLATION-STAGE-1  all  --  *      *       0.0.0.0/0            0.0.0.0/0           
    0     0 ACCEPT     all  --  *      docker0  0.0.0.0/0            0.0.0.0/0            ctstate RELATED,ESTABLISHED
    0     0 DOCKER     all  --  *      docker0  0.0.0.0/0            0.0.0.0/0           
    0     0 ACCEPT     all  --  docker0 !docker0  0.0.0.0/0            0.0.0.0/0           
    0     0 ACCEPT     all  --  docker0 docker0  0.0.0.0/0            0.0.0.0/0           
    0     0 ACCEPT     all  --  *      docker_gwbridge  0.0.0.0/0            0.0.0.0/0            ctstate RELATED,ESTABLISHED
    0     0 DOCKER     all  --  *      docker_gwbridge  0.0.0.0/0            0.0.0.0/0           
    0     0 ACCEPT     all  --  docker_gwbridge !docker_gwbridge  0.0.0.0/0            0.0.0.0/0           
    0     0 DROP       all  --  docker_gwbridge docker_gwbridge  0.0.0.0/0            0.0.0.0/0           

Chain OUTPUT (policy ACCEPT 114M packets, 18G bytes)
 pkts bytes target     prot opt in     out     source               destination         

Chain DOCKER (2 references)
 pkts bytes target     prot opt in     out     source               destination         

Chain DOCKER-ISOLATION-STAGE-1 (1 references)
 pkts bytes target     prot opt in     out     source               destination         
    0     0 DOCKER-ISOLATION-STAGE-2  all  --  docker0 !docker0  0.0.0.0/0            0.0.0.0/0           
    0     0 DOCKER-ISOLATION-STAGE-2  all  --  docker_gwbridge !docker_gwbridge  0.0.0.0/0            0.0.0.0/0           
    0     0 RETURN     all  --  *      *       0.0.0.0/0            0.0.0.0/0           

Chain DOCKER-ISOLATION-STAGE-2 (2 references)
 pkts bytes target     prot opt in     out     source               destination         
    0     0 DROP       all  --  *      docker0  0.0.0.0/0            0.0.0.0/0           
    0     0 DROP       all  --  *      docker_gwbridge  0.0.0.0/0            0.0.0.0/0           
    0     0 RETURN     all  --  *      *       0.0.0.0/0            0.0.0.0/0           

Chain DOCKER-USER (1 references)
 pkts bytes target     prot opt in     out     source               destination         
    0     0 RETURN     all  --  *      *       0.0.0.0/0            0.0.0.0/0           

I asked a similar question years ago.

Now, my machine has four 1G hugepages and 256 2MB hugepages:

# cat /sys/devices/system/node/node0/hugepages/hugepages-1048576kB/nr_hugepages
4
# cat /sys/devices/system/node/node0/hugepages/hugepages-2048kB/nr_hugepages
256

But then numstat -vm shows:

Per-node system memory usage (in MBs):
                          Node 0           Total
                 --------------- ---------------
MemTotal                65205.89        65205.89
MemFree                 58656.55        58656.55
MemUsed                  6549.34         6549.34
Active                    158.62          158.62
Inactive                   89.90           89.90
Active(anon)               15.32           15.32
Inactive(anon)              9.04            9.04
Active(file)              143.30          143.30
Inactive(file)             80.86           80.86
Unevictable                10.69           10.69
Mlocked                    10.69           10.69
Dirty                       0.02            0.02
Writeback                   0.00            0.00
FilePages                 235.87          235.87
Mapped                     16.08           16.08
AnonPages                  23.42           23.42
Shmem                       9.43            9.43
KernelStack                 5.38            5.38
PageTables                  2.84            2.84
NFS_Unstable                0.00            0.00
Bounce                      0.00            0.00
WritebackTmp                0.00            0.00
Slab                       50.60           50.60
SReclaimable               23.14           23.14
SUnreclaim                 27.46           27.46
AnonHugePages               0.00            0.00
HugePages_Total          4096.00         4096.00
HugePages_Free           4096.00         4096.00
HugePages_Surp              0.00            0.00

Based on the answer for my previous post, 4096 should be an "unit". Now, I am confused. Unit of what here?

It seems to me the "unit" is "MB" and numastat doesn't include those 2MB hugepages?

And why 2MB hugepages aren't reported here?

I am looking for a daemon utility to track all non local TCP connections and which binaries establish the TCP connections (actively and passively) with which IPs and ports.

auditd seems like a great tool.

Following this post, I notice that the following rule captures all connections: auditctl -a exit,always -F arch=b64 -S connect -k MYCONNECT

I see many entries like these:

type=SOCKADDR msg=audit(04/01/2021 10:54:23.327:397) : saddr={ fam=local path=/dev/log } 
type=SYSCALL msg=audit(04/01/2021 10:54:23.327:397) : arch=x86_64 syscall=connect success=yes exit=0 a0=0x4 a1=0x7fc64b29a6c0 a2=0x6e a3=0x20656c62616e6520 items=1 ppid=3116 pid=3156 auid=root uid=root gid=root euid=root suid=root fsuid=root egid=root sgid=root fsgid=root tty=pts0 ses=2 comm=sudo exe=/usr/bin/sudo key=MYCONNECT 
type=SOCKADDR msg=audit(04/01/2021 10:54:23.328:403) : saddr={ fam=local path=/var/run/dbus/system_bus_socket } 
type=SYSCALL msg=audit(04/01/2021 10:54:23.328:403) : arch=x86_64 syscall=connect success=yes exit=0 a0=0x4 a1=0x55e28814cac8 a2=0x21 a3=0x7fff6e3462d0 items=1 ppid=3116 pid=3156 auid=root uid=root gid=root euid=root suid=root fsuid=root egid=root sgid=root fsgid=root tty=pts0 ses=2 comm=sudo exe=/usr/bin/sudo key=MYCONNECT 

I wonder whether there is a way to filter by the AF family, limiting to IPv4 and IPv6.

I can add a filter to capture socket system call with AF family = IPv4 or IPv6. But for connect system call, I am not sure how to do so.

Thanks.

# fio --name=random-write --directory=/mnt/test/ --ioengine=posixaio --rw=randwrite -bs=4k --numjobs=1 --size=4g -iodepth=1 -runtime=600 --time_based --end_fsync=1
random-write: (g=0): rw=randwrite, bs=(R) 4096B-4096B, (W) 4096B-4096B, (T) 4096B-4096B, ioengine=posixaio, iodepth=1
fio-3.7
Starting 1 process
random-write: Laying out IO file (1 file / 4096MiB)
Jobs: 1 (f=1): [w(1)][100.0%][r=0KiB/s,w=0KiB/s][r=0,w=0 IOPS][eta 00m:00s]    

Any idea why it returned after 60 mins rather than 600 seconds that I set?

I checked dmesg, no error:

[Mon Mar  1 20:53:36 2021] XFS (sda2): Mounting V5 Filesystem
[Mon Mar  1 20:53:37 2021] XFS (sda2): Starting recovery (logdev: internal)
[Mon Mar  1 20:53:45 2021] XFS (sda2): Ending recovery (logdev: internal)

I ran the same command on another drive (a SSD instead) on the same box at the same time, and it finished on time and returned.

Thanks in advance!

Before I tried to partition a 10TB HDD again, parted saw it:

# parted /dev/sdb
(parted) print list                                                       
Model: ATA ST10000NM0016-1T (scsi)
Disk /dev/sdb: 10.0TB
Sector size (logical/physical): 512B/4096B
Partition Table: gpt
Disk Flags: 

Number  Start   End     Size    File system  Name     Flags
 1      1049kB  10.0TB  10.0TB  xfs          primary
....
....
....

Then, I just tried to partition again but failed:

[root@localhost ~]# parted /dev/sdb
GNU Parted 3.1
Using /dev/sdb
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) mklabel gpt                                                      
Warning: The existing disk label on /dev/sdb will be destroyed and all data on this disk will be lost. Do you want to continue?
Yes/No? Yes
Error: end of file while reading /dev/sdb
Retry/Ignore/Cancel? Retry                                                
Error: end of file while reading /dev/sdb
Retry/Ignore/Cancel? Cancel                                               
(parted) q                                                                
Warning: Error fsyncing/closing /dev/sdb: Input/output error
Retry/Ignore? Retry                                                       
Warning: Error fsyncing/closing /dev/sdb: Input/output error
Retry/Ignore? Ignore                                                      

Then, the drive disappeared. I tried to reboot but still couldn't see the drive.

This post suggested to use gdisk /dev/sdb. However, I think it is so corrupted that gdisk can't recognize it:

# gdisk -l /dev/sdb
GPT fdisk (gdisk) version 0.8.10

Problem opening /dev/sdb for reading! Error is 2.
The specified file does not exist!

lsbk's output:

# lsblk 
NAME                 MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
sda                    8:0    1 447.1G  0 disk 
├─sda1                 8:1    1     2G  0 part /boot
└─sda2                 8:2    1 445.1G  0 part 
  ├─centos-root      253:0    0    30G  0 lvm  /
  ├─centos-swap      253:1    0     4G  0 lvm  [SWAP]
  ├─centos-var       253:2    0    30G  0 lvm  /var
  ├─centos-coredumps 253:3    0    30G  0 lvm  /coredumps
  └─centos-latest    253:4    0 351.1G  0 lvm  /latest

ls -ltr /dev/sd*'s output:

brw-rw---- 1 root disk 8, 0 Feb 10 16:00 /dev/sda
brw-rw---- 1 root disk 8, 2 Feb 10 16:00 /dev/sda2
brw-rw---- 1 root disk 8, 1 Feb 10 16:00 /dev/sda1

lshw -class disk, parted -l and fdisk -l also don't see the drive.

I see something fishy in dmesg:

[Wed Feb 10 13:27:39 2021] ata13: softreset failed (1st FIS failed)
[Wed Feb 10 13:27:49 2021] ata13: softreset failed (device not ready)
[Wed Feb 10 13:28:06 2021] ata13: SATA link up 6.0 Gbps (SStatus 133 SControl 300)
[Wed Feb 10 13:28:11 2021] ata13.00: qc timeout (cmd 0xec)
[Wed Feb 10 13:28:11 2021] ata13.00: failed to IDENTIFY (I/O error, err_mask=0x4)
[Wed Feb 10 13:28:17 2021] ata13: link is slow to respond, please be patient (ready=0)
[Wed Feb 10 13:28:21 2021] ata13: softreset failed (device not ready)
[Wed Feb 10 13:28:31 2021] ata13: softreset failed (1st FIS failed)
[Wed Feb 10 13:28:41 2021] ata13: SATA link up 6.0 Gbps (SStatus 133 SControl 300)
[Wed Feb 10 13:28:51 2021] ata13.00: qc timeout (cmd 0xec)
[Wed Feb 10 13:28:51 2021] ata13.00: failed to IDENTIFY (I/O error, err_mask=0x4)
[Wed Feb 10 13:28:51 2021] ata13: limiting SATA link speed to 3.0 Gbps
[Wed Feb 10 13:28:52 2021] ata13: SATA link up 3.0 Gbps (SStatus 123 SControl 320)
[Wed Feb 10 13:29:13 2021] ata13.00: qc timeout (cmd 0x47)
[Wed Feb 10 13:29:13 2021] ata13.00: READ LOG DMA EXT failed, trying unqueued
[Wed Feb 10 13:29:13 2021] ata13.00: failed to get NCQ Send/Recv Log Emask 0x40
[Wed Feb 10 13:29:13 2021] ata13.00: ATA-10: ST10000NM0016-1TT101, SNE0, max UDMA/133
[Wed Feb 10 13:29:13 2021] ata13.00: 19532873728 sectors, multi 16: LBA48 NCQ (depth 31/32), AA
[Wed Feb 10 13:29:13 2021] ata13.00: failed to set xfermode (err_mask=0x40)
[Wed Feb 10 13:29:13 2021] ata13.00: disabled
[Wed Feb 10 13:29:13 2021] ata13: hard resetting link
[Wed Feb 10 13:29:23 2021] ata13: softreset failed (1st FIS failed)
[Wed Feb 10 13:29:23 2021] ata13: hard resetting link
[Wed Feb 10 13:29:33 2021] ata13: softreset failed (device not ready)
[Wed Feb 10 13:29:33 2021] ata13: hard resetting link
[Wed Feb 10 13:29:39 2021] ata13: link is slow to respond, please be patient (ready=0)
[Wed Feb 10 13:29:49 2021] ata13: SATA link up 3.0 Gbps (SStatus 123 SControl 320)
[Wed Feb 10 13:29:49 2021] ata13: EH complete

=================================

Update #1

I read this article and turned off acpi, and another article suggested power issue and so I turned off tune-adm. Then, the disk came back and I ran parted /dev/sdb with mklabel gpt just like last time, but this time, no Error: end of file while reading /dev/sdb, but then when I continued to mkpart primary xfs 0% 1%, it gave me Error: /dev/sdb: unrecognised disk label. I rebooted the machine and tried again:

(parted) mkpart primary xfs 0% 1%                                         
(parted) mkpart primary xfs 1% 2%                                         
(parted) mkpart primary ext4 2% 3%                                        
(parted) mkpart primary ext4 3% 4%
(parted) mkpart primary btrfs 4% 5%                                       
(parted) mkpart primary btrfs 5% 6%                                       
(parted) mkpart primary xfs 6% 100%                                       
(parted) print                                                            
Model: ATA ST10000NM0016-1T (scsi)
Disk /dev/sdb: 10.0TB
Sector size (logical/physical): 512B/4096B
Partition Table: gpt
Disk Flags: 

Number  Start   End     Size    File system  Name     Flags
 1      1049kB  100GB   100GB   xfs          primary
 2      100GB   200GB   100GB                primary
 3      200GB   300GB   100GB                primary
 4      300GB   400GB   100GB                primary
 5      400GB   500GB   100GB                primary
 6      500GB   600GB   100GB                primary
 7      600GB   10.0TB  9401GB               primary

(parted) q                                                                

It works. But it seems so unstable. And I checked dmesg again, and found similar but different failures:

[Thu Feb 11 00:58:31 2021] ata15.00: qc timeout (cmd 0xec)
[Thu Feb 11 00:58:31 2021] ata15.00: failed to IDENTIFY (I/O error, err_mask=0x4)
[Thu Feb 11 00:58:32 2021] ata15: SATA link up 6.0 Gbps (SStatus 133 SControl 300)
[Thu Feb 11 00:58:42 2021] ata15.00: qc timeout (cmd 0xec)
[Thu Feb 11 00:58:42 2021] ata15.00: failed to IDENTIFY (I/O error, err_mask=0x4)
[Thu Feb 11 00:58:42 2021] ata15: limiting SATA link speed to 3.0 Gbps
[Thu Feb 11 00:58:44 2021] ata15: SATA link up 3.0 Gbps (SStatus 123 SControl 320)
[Thu Feb 11 00:59:12 2021] ata15.00: ATA-10: ST10000NM0016-1TT101, SNE0, max UDMA/133
[Thu Feb 11 00:59:12 2021] ata15.00: 19532873728 sectors, multi 16: LBA48 NCQ (depth 31/32), AA
[Thu Feb 11 00:59:12 2021] ata15.00: configured for UDMA/133
[Thu Feb 11 00:59:12 2021] scsi 14:0:0:0: Direct-Access     ATA      ST10000NM0016-1T SNE0 PQ: 0 ANSI: 5
[Thu Feb 11 00:59:12 2021] sd 14:0:0:0: [sdb] 19532873728 512-byte logical blocks: (10.0 TB/9.09 TiB)
[Thu Feb 11 00:59:12 2021] sd 14:0:0:0: [sdb] 4096-byte physical blocks
[Thu Feb 11 00:59:12 2021] sd 14:0:0:0: [sdb] Write Protect is off
[Thu Feb 11 00:59:12 2021] sd 14:0:0:0: [sdb] Mode Sense: 00 3a 00 00
[Thu Feb 11 00:59:12 2021] sd 14:0:0:0: [sdb] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
[Thu Feb 11 00:59:19 2021]  sdb:
[Thu Feb 11 00:59:19 2021] sd 14:0:0:0: [sdb] Attached SCSI removable disk
[Thu Feb 11 00:59:37 2021] SGI XFS with ACLs, security attributes, no debug enabled

Any idea what's going on?

Thanks.

I have the following service:

[Unit]
Description=foo

[Service]
Type=oneshot
RemainAfterExit=true
ExecStop=/opt/script/bar.sh

[Install]
WantedBy=multi-user.target

And bar.sh:

#!/bin/bash
echo 1 > /sys/bus/workqueue/devices/writeback/cpumask
cat /sys/bus/workqueue/devices/writeback/cpumask > /tmp/writeback

Then after I rebooted, cat /tmp/writeback looks good: 000000,00000000,00000000,00000000,00000000,00000000,00000000,00000001

But /sys/bus/workqueue/devices/writeback/cpumask got overwritten back to default:

ffffff,ffffffff,ffffffff,ffffffff,ffffffff,ffffffff,ffffffff,ffffffff

Thought?

$ numastat -vm

Per-node system memory usage (in MBs):
                          Node 0           Total
                 --------------- ---------------
MemTotal                32464.24        32464.24
MemFree                 30993.97        30993.97
MemUsed                  1470.27         1470.27
Active                     47.68           47.68
Inactive                  158.69          158.69
Active(anon)               10.48           10.48
Inactive(anon)              8.99            8.99
Active(file)               37.21           37.21
Inactive(file)            149.70          149.70
Unevictable                 0.00            0.00
Mlocked                     0.00            0.00
Dirty                       0.00            0.00
Writeback                   0.00            0.00
FilePages                 196.26          196.26
Mapped                     13.79           13.79
AnonPages                   9.82            9.82
Shmem                       9.36            9.36
KernelStack                 3.86            3.86
PageTables                  1.91            1.91
NFS_Unstable                0.00            0.00
Bounce                      0.00            0.00
WritebackTmp                0.00            0.00
Slab                       41.54           41.54
SReclaimable               17.00           17.00
SUnreclaim                 24.54           24.54
AnonHugePages               0.00            0.00
HugePages_Total           256.00          256.00
HugePages_Free            254.00          254.00
HugePages_Surp              0.00            0.00
$ ll /mnt/huge2m/
total 2048
-rw-rw-rw- 1 as as 2097152 Dec 18 20:32 request.0
-rw-rw-rw- 1 as as 2097152 Dec 18 20:32 response.0

For some reason, even tho two 2MB hugepages (request.0 and response.0 exists), only 1 is counted? As numastat states there is 256MB total of hugepages and 254MB are free.

Idea?

Here is the sequence of events:

1. I added my RSA key to .ssh/[my admin user], updated permission, and disabled SSH authentication by password months ago.
2. I formatted my desktop and I forgot to re-enable the SSH authentication by password.
3. Then, my newly configured desktop can't SSH into the NAS.

I tried to update my newly generated RSA key via DSM web GUI -- File Station>Homes>[my admin user]/.ssh/authorized_keys

But I still can't ssh, here is the tail of the ssh output in verbose mode:

debug1: Found key in /home/hc/.ssh/known_hosts:6
debug3: send packet: type 21
debug2: set_newkeys: mode 1
debug1: rekey after 134217728 blocks
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug3: receive packet: type 21
debug1: SSH2_MSG_NEWKEYS received
debug2: set_newkeys: mode 0
debug1: rekey after 134217728 blocks
debug2: key: /home/hc/.ssh/id_rsa (0x55c5c982c140), agent
debug2: key: /home/hc/.ssh/id_dsa ((nil))
debug2: key: /home/hc/.ssh/id_ecdsa ((nil))
debug2: key: /home/hc/.ssh/id_ed25519 ((nil))
debug3: send packet: type 5
debug3: receive packet: type 7
debug1: SSH2_MSG_EXT_INFO received
debug1: kex_input_ext_info: server-sig-algs=<ssh-ed25519,ssh-rsa,ssh-dss,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521>
debug3: receive packet: type 6
debug2: service_accept: ssh-userauth
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug3: send packet: type 50
debug3: receive packet: type 51
debug1: Authentications that can continue: publickey
debug3: start over, passed a different list publickey
debug3: preferred gssapi-keyex,gssapi-with-mic,publickey,keyboard-interactive,password
debug3: authmethod_lookup publickey
debug3: remaining preferred: keyboard-interactive,password
debug3: authmethod_is_enabled publickey
debug1: Next authentication method: publickey
debug1: Offering RSA public key: /home/hc/.ssh/id_rsa
debug3: send_pubkey_test
debug3: send packet: type 50
debug2: we sent a publickey packet, wait for reply
debug3: receive packet: type 51
debug1: Authentications that can continue: publickey
debug1: Trying private key: /home/hc/.ssh/id_dsa
debug3: no such identity: /home/hc/.ssh/id_dsa: No such file or directory
debug1: Trying private key: /home/hc/.ssh/id_ecdsa
debug3: no such identity: /home/hc/.ssh/id_ecdsa: No such file or directory
debug1: Trying private key: /home/hc/.ssh/id_ed25519
debug3: no such identity: /home/hc/.ssh/id_ed25519: No such file or directory
debug2: we did not send a packet, disable method
debug1: No more authentication methods to try.
Permission denied (publickey).

I wonder whether:

1. there is a way to access /etc/ssh/sshd_config on the NAS via DSM web GUI; or
2. there is a way to fix my /home/[my admin user]/.ssh/authorized_keys; or
3. there is a way that I can regain my SSH access...I do have physical access to my NAS.

Synology support suggested that I hard-reset the NAS. I prefer not to if there is a better option because I have too many things configured.

Info:

• DSM 6.2.2-24922
• DS1019+

According to man yumdownloader:

   --resolve
          When downloading RPMs, resolve dependencies and also download the required packages.

However, when I tried:

$ sudo yumdownloader devtoolset-7-gcc-c++.x86_64 --destdir /opt/downloaded_rpms/ --resolve

It didn't download the dependency:

$ ll /opt/downloaded_rpms/
total 11644
-rw-r--r-- 1 root root 11683460 Dec 25 17:10 devtoolset-7-gcc-c++-7.2.1-1.el7.sc1.x86_64.rpm

And so when I attempted to install, it complained:

# sudo yum install /tmp/devtoolset-7-gcc-c++-7.2.1-1.el7.sc1.x86_64.rpm 
Loaded plugins: fastestmirror
Examining /tmp/devtoolset-7-gcc-c++-7.2.1-1.el7.sc1.x86_64.rpm: devtoolset-7-gcc-c++-7.2.1-1.el7.sc1.x86_64
Marking /tmp/devtoolset-7-gcc-c++-7.2.1-1.el7.sc1.x86_64.rpm to be installed
Resolving Dependencies
--> Running transaction check
---> Package devtoolset-7-gcc-c++.x86_64 0:7.2.1-1.el7.sc1 will be installed
--> Processing Dependency: devtoolset-7-gcc = 7.2.1-1.el7.sc1 for package: devtoolset-7-gcc-c++-7.2.1-1.el7.sc1.x86_64
...
...
--> Processing Dependency: devtoolset-7-libstdc++-devel = 7.2.1-1.el7.sc1 for package: devtoolset-7-gcc-c++-7.2.1-1.el7.sc1.x86_64
--> Processing Dependency: devtoolset-7-runtime for package: devtoolset-7-gcc-c++-7.2.1-1.el7.sc1.x86_64
--> Finished Dependency Resolution
Error: Package: devtoolset-7-gcc-c++-7.2.1-1.el7.sc1.x86_64 (/devtoolset-7-gcc-c++-7.2.1-1.el7.sc1.x86_64)
           Requires: devtoolset-7-gcc = 7.2.1-1.el7.sc1
Error: Package: devtoolset-7-gcc-c++-7.2.1-1.el7.sc1.x86_64 (/devtoolset-7-gcc-c++-7.2.1-1.el7.sc1.x86_64)
           Requires: devtoolset-7-libstdc++-devel = 7.2.1-1.el7.sc1
Error: Package: devtoolset-7-gcc-c++-7.2.1-1.el7.sc1.x86_64 (/devtoolset-7-gcc-c++-7.2.1-1.el7.sc1.x86_64)
           Requires: devtoolset-7-runtime
 You could try using --skip-broken to work around the problem
 You could try running: rpm -Va --nofiles --nodigest

Did I do something wrong?

Thanks!

I have a CentOS 7 server (server X)in a datacenter that has a firewall that I couldn't do yum:

# yum search htop
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
Could not retrieve mirrorlist http://mirrorlist.centos.org/?release=7&arch=x86_64&repo=os&infra=stock error was
14: curl#6 - "Could not resolve host: mirrorlist.centos.org; Unknown error"
Could not retrieve mirrorlist http://mirrorlist.centos.org/?release=7&arch=x86_64&repo=extras&infra=stock error was
14: curl#6 - "Could not resolve host: mirrorlist.centos.org; Unknown error"
Could not retrieve mirrorlist http://mirrorlist.centos.org/?release=7&arch=x86_64&repo=updates&infra=stock error was
14: curl#6 - "Could not resolve host: mirrorlist.centos.org; Unknown error"
 * base: mirrors.163.com
 * extras: mirrors.shu.edu.cn
 * updates: ftp.sjtu.edu.cn
Warning: No matches found for: htop
No matches found

And the datacenter doesn't offer a proxy server for me to yum install anything.

However, I can ssh to server X from my home computer over Internet + VPN.

I just wonder whether there is a way to utilize the ssh connection to yum install packages (or any other ways to yum install packages).

This post suggested that people just install with RPMs or DVD.

I think installing from RPMs are simple if there isn't any dependency but it will be troublesome to deal with dependency.

Any suggestion is welcome.

Thanks in advance!

Update 1: I couldn't even ping the IP of mirrorlist.centos.org (although it is pingable):

# ping 85.236.43.108
PING 85.236.43.108 (85.236.43.108) 56(84) bytes of data.
^C
--- 85.236.43.108 ping statistics ---
3 packets transmitted, 0 received, 100% packet loss, time 1999ms

So the DNS resolution isn't the root cause.

Traceroute indicates the traffic is blocked:

# traceroute 85.236.43.108
traceroute to 85.236.43.108 (85.236.43.108), 30 hops max, 60 byte packets
 1  gateway (172.18.22.254)  3.884 ms  4.100 ms  4.322 ms
 2  gateway (172.18.22.254)  3.200 ms !H * *

It couldn't go out because the datacenter has a firewall. Server X itself has no firewall nor iptable to prevent going out.

Update 2: downloading rpms and rsync-ing and then installing failed

# yum localinstall /tmp/audit-libs-2.8.1-3.el7.x86_64.rpm --disablerepo=*
Loaded plugins: fastestmirror
Examining /tmp/audit-libs-2.8.1-3.el7.x86_64.rpm: audit-libs-2.8.1-3.el7.x86_64
Marking /tmp/audit-libs-2.8.1-3.el7.x86_64.rpm as an update to audit-libs-2.7.6-3.el7.x86_64
Resolving Dependencies
--> Running transaction check
---> Package audit-libs.x86_64 0:2.7.6-3.el7 will be updated
--> Processing Dependency: audit-libs(x86-64) = 2.7.6-3.el7 for package: audit-2.7.6-3.el7.x86_64
Loading mirror speeds from cached hostfile
---> Package audit-libs.x86_64 0:2.8.1-3.el7 will be an update
--> Finished Dependency Resolution
Error: Package: audit-2.7.6-3.el7.x86_64 (@anaconda)
           Requires: audit-libs(x86-64) = 2.7.6-3.el7
           Removing: audit-libs-2.7.6-3.el7.x86_64 (@anaconda)
               audit-libs(x86-64) = 2.7.6-3.el7
           Updated By: audit-libs-2.8.1-3.el7.x86_64 (/audit-libs-2.8.1-3.el7.x86_64)
               audit-libs(x86-64) = 2.8.1-3.el7
 You could try using --skip-broken to work around the problem
 You could try running: rpm -Va --nofiles --nodigest