I am trying to ssh to remote machine, the attempt fails: $ ssh -vvv admin@192.168.100.14 OpenSSH_7.7p1, OpenSSL 1.0.2o 27 Mar 2018 ..... debug2: ciphers ctos: aes128-cbc,3des-cbc,aes192-cbc,aes256-cbc debug2: ciphers stoc: aes128-cbc,3des-cbc,aes192-cbc,aes256-cbc debug2: MACs ctos: umac-64-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,hmac-sha1-etm@openssh.com,umac-64@openssh.com,umac-128@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-sha1 debug2: MACs stoc: umac-64-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,hmac-sha1-etm@openssh.com,umac-64@openssh.com,umac-128@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-sha1 debug2: compression ctos: none,zlib@openssh.com debug2: compression stoc: none,zlib@openssh.com debug2: languages ctos: debug2: languages stoc: debug2: first_kex_follows 0 debug2: reserved 0 debug1: kex: algorithm: curve25519-sha256 debug1: kex: host key algorithm: rsa-sha2-512 Unable to negotiate with 192.168.100.14 port 22: no matching cipher found. Their offer: aes128-cbc,3des-cbc,aes192-cbc,aes256-cbc As far as I understand the last string of the log, the server offers to use one of the following 4 cipher algorithms: aes128-cbc,3des-cbc,aes192-cbc,aes256-cbc. Looks like my ssh client doesn't support any of them, so the server and client are unable to negotiate further. But my client does support all the suggested algorithms: $ ssh -Q cipher 3des-cbc aes128-cbc aes192-cbc aes256-cbc rijndael-cbc@lysator.liu.se aes128-ctr ... and there are several more. And if I explicitly specify the algorithm like this: ssh -vvv -c aes256-cbc admin@192.168.100.14 I can successfully login to the server. My ~/.ssh/config doesn't contain any cipher-related directives (actually I removed it completely, but the problem remains). So, why client and server can't decide which cipher to use without my explicit instructions? The client understands that server supports aes256-cbc, client understands that he can use it himself, why not just use it? Some additional notes: - There was no such problem some time (about a month) ago. I've not changed any ssh configuration files since then. I did update installed packages though. - There is a question which describes very similar-looking problem, but there is no answer my question: https://unix.stackexchange.com/questions/402746 UPDATE: problem solved As telcoM explained the problem is with server: it suggests only the obsolete cipher algorithms. I was sure that both client and server are not outdated. I have logged into server (by the way, it's Synology, updated to latest available version), and examined the /etc/ssh/sshd_config. The very first (!) line of this file was: Ciphers aes128-cbc,3des-cbc,aes192-cbc,aes256-cbc This is very strange (the fact that line is very first in the file), I am sure I've never touched the file before. However I've changed the line to: Ciphers aes256-ctr,aes128-cbc,3des-cbc,aes192-cbc,aes256-cbc restarted the server (did not figure out how to restart the sshd service only), and now the problem is gone: I can ssh to server as usual.

I want to edit the sudoers file on my Synology Disk Station (specifically, to enabled password-less shutdown), however my version of Synology DSM does not have visudo installed. How can I install it so I can safely edit the sudoers file?

I have Synology DS923+ NAS with 32 GB memory and two hard drives in RAID1. It runs Linux 4.4 with the ext4 filesystem. Copying a 20GB file from my laptop to NAS using SMB with 10GbE wired ethernet the transfer is 500MB/s, but after 10%, slower than 100MB/s (same as direct HDD write speed). I changed to vm.dirty_ratio from 30% to 90%. It's ok. It use 4% when normal idle. and changed to vm.dirty_background_ratio from 10% to 3% for faster cache flushing. And... It sends more than 500MB/s to 90%. but last 10% was slowing down: What else can I do to make sure that even in the last 10%, I'm still getting the maximum transfer speed of the network?

I logged in as root and tried to recursively delete the folder /volume2/Name using rm -rf It started and deleted all the files/directories inside this folder Name, but it cannot remove the folder itself even though I am root: rm: cannot remove 'Name’: Operation not permitted The command ls -l list the permissions for this folder as: d---------+ 1 root root Synology has a special tool called synoacltool for these ACL permissions, but I don't know to use it. So what do I need to do in order to be able to remove this (empty) folder?

I have several Synology NAS, running DSM 6.2.2-24922 Update 5, which I successfully mount on Ubuntu 18.04 with: sudo mount -t cifs //192.168.x.y/folder_name -o username=user,password=???????,uid=1000,sec=ntlm,vers=1.0 /local_mount_point I have bought a new one, which is running DSM 6.2.4-25556. I attempt to mount in the same way and I get this error: mount: /local_mount_point: mount(2) system call failed: Operation not supported. EDIT I removed the vers=1.0, and the error changed to //192.168.x.y/folder_name does not exist Enable SMB Share is enabled on the new NAS, with the same settings as the others. My smb.conf on the new NAS is: [global] printcap name=cups winbind enum groups=yes include=/var/tmp/nginx/smb.netbios.aliases.conf min protocol=SMB2 security=user local master=no realm=* passdb backend=smbpasswd printing=cups max protocol=SMB3 winbind enum users=yes load printers=yes workgroup=WORKGROUP And my smb.share.conf is: [folder_name] recycle bin admin only=yes ftp disable modify=no ftp disable download=no write list=nobody,nobody browseable=yes mediaindex=no hide unreadable=no win share=yes enable recycle bin=yes invalid users=nobody,nobody read list=nobody,nobody ftp disable list=no edit synoacl=yes valid users=nobody,nobody writeable=yes guest ok=yes path=/volume2/folder_name_1 skip smb perm=yes comment="" [folder_name_2] recycle bin admin only=yes ftp disable modify=no ftp disable download=no write list=nobody,nobody browseable=yes mediaindex=no hide unreadable=no win share=yes enable recycle bin=yes invalid users=nobody,nobody read list=nobody,nobody ftp disable list=no edit synoacl=yes valid users=nobody,nobody writeable=yes guest ok=yes path=/volume1/folder_name_2 skip smb perm=yes comment="" (For interest, the smb.conf on one of the NAS which are working is: [global] printcap name=cups winbind enum groups=yes include=/var/tmp/nginx/smb.netbios.aliases.conf security=user local master=no realm=* passdb backend=smbpasswd printing=cups max protocol=SMB2 winbind enum users=yes load printers=yes workgroup=WORKGROUP ) Can anyone advise?

I have some files on synology disk that I would like to recover with extundelete. I have mounted the raid1 setup. So on the disk is two raid storages (md2 and md3) and they are connected to one with lvm. I try to get the lvm going. I think it doesn't like the md2p1. I tried to mount md2p1, but it doesn't mount, so I thnik it's some garbage. How could I make that work that LVM would find the other device? sudo lsblk -o name,uuid,mountpoint NAME UUID MOUNTPOINT sda ├─sda1 bb4b1f59-9349-4e59-cced-5de7ca715931 ├─sda2 291dec99-01d5-7031-cced-5de7ca715931 ├─sda5 46288321-39d3-353d-7014-c3a9333d1c33 │ └─md2 8s9LfU-Egt2-sbtJ-1zkH-ewqb-LjRT-xZ2RC2 │ └─md2p1 8da77aa4-43ff-4cd1-81f0-f311284e0b04 └─sda6 a7ff03a3-29c2-a100-ecdd-c31c151ca783 └─md3 Eu0fsK-Cu1W-3PCw-ZEV6-80fL-05rf-H0qlcE sdb ├─sdb1 e29faa0c-a7b4-4851-a17d-75c20238edc2 / ├─sdb2 ce06f4bb-5f73-423b-9794-b94a1e47d4f8 └─sdb3 6089A7F658D702D4 sdc └─sdc1 09d3c590-3a6a-4436-8718-7c14ab0e282b sudo lvs Couldn't find device with uuid 8s9LfU-Egt2-sbtJ-1zkH-ewqb-LjRT-xZ2RC2. LV VG Attr LSize Pool Origin Data% Move Log Copy% Convert lv vg1000 -wi-----p 2,72t

I'm getting a "Display all possibilities? (y or n)" dialogue in a PuTTY Terminal connected to a Synology NAS. The Synology Support people are abdicating responsibility for this, so I'm wondering if someone can help to identify the source? I'm connecting with a PuTTY Terminal, using the Default Config: just login with user & password & wait...
...after a long wait (an hour, say) the "Display all possibilities" message appears. ps -ef suggested the Session is running a Bourne Shell ("sh") but $SHELL --version yields:
GNU bash, version 4.4.23(1)-release (x86_64-pc-linux-gnu) The reported OS is: Linux 4.4.302+ x86_64 There were no user-written scripts/processes running on the NAS. Pure Synology. During the wait, no input of any kind was made at the Terminal.
In that time, the NAS Filesystem was not accessed.
Neither was the Synology Console used (although it was open, displaying the Control Panel App). Is there some way my own Session can be issuing a Command without my knowledge?
(there was absolutely no spurious input - Tabs, or otherwise - after the login) Could some other Process be displaying the message on my Terminal? I'd be grateful for any ideas how I can get to the bottom of this and/or put a stop to it. Thanks in advance. **Screenshot 1, after login:** **Screenshot 2, after long wait:** **Screenshot 3, after entering "y":**

With Synology DSM 6 it seems that SSH requires users to be members of the admin group. However, even in this case there seem to be problems with file/directory permissions that prevent key-based authentication succeeding for non-root users (standard /root/.ssh/authorized_keys works OK for root). Specifically, SSH key-based authentication fails even with a correct ~/.ssh/authorized_keys in place.

I've been running a new Synology RS3621RPxs for several weeks, and my 4TB SSD cache shows: Cache composition: Reusable (341 GB) / Total (3.6 TB) If I'm reading that correctly, my nas isn't even using 10% of the available SSD cache. According to the Synology website this was the right size for my array, but it seems like overkilL! My cache hit rate is around 85% The NAS is used primarily as an NFS data store for other hosts using ESXi. (So large VMDK files primarily). This SSD is a RO cache (single SSD), and I'm thinking of switching to a pair of NVMe sticks for RW cache. But, what size should I buy? Does RW cache increase demands? I hate to spend the money on 2x4TB of cache if most will go unused!

I am sending data from one Synology NAS to another Synology NAS using the rsync protocol (using bash script). It works, great but I noticed that if I do not have the rsync service enabled on the destination NAS the source (client) rsync will fail with rsync error: rsync service is no running (code 43) at io.c(254) [sender=3.1.2] This doesn't make sense since I'm running rsync as follows on the source(client): rsync -av -e ssh SOURCE USER@DESTINATION:/PATH Shouldn't this FORCE the rsync traffic over ssh? Why do I need the rsync service enabled on the destination (server) side? (Any Synology experts who can comment on whether Synology's own rsync binary does something special)

I have a new Synology NAS with 2 storage pools, and I have one volume per pool. I have added a single SSD to the NAS to serve as a cache, and was able to add it to the first storage pool. This is a fairly large SSD (4TB), so I would like to share it with the second storage pool. However, I am unable to add it to the second storage pool. According to the Synology Online Guide "SSD cache group supports cache creation on multiple volumes". Perhaps I misinterpreted this statement! Can I use my large SSD to provide caching for multiple volumes, across multiple storage pools? (I can't believe they want me to add 1 SSD for each storage pool) I'm using a SATA SSD in case that matters. I read that (I think) I can use NVMe card as cache instead. Does that behave the same way? (There are only 2 NVMe slots, so that would mean max 2 storage pools can be read cached, or 1 storage pool r+w cached).

I have a new Synology NAS (DS1621+), and have begun integration into my home network. I'm having some problems using it with my Linux hosts. I can mount the NAS, but the permissions (as seen from Linux) are not what I want them to be. I'm under the impression that ownership & permissions can be *"mapped"* from the NAS to my Linux clients, but it's unclear to me how this is done. My Linux hosts are all Debian-based units, and file services provided by the Synology NAS are via SMB. From Linux, I use the *cifs-utils suite* (mount -t cifs ...) to mount the shares. I've contacted Synology, and was surprised to learn: **1:** Synology does not provide tech support to "command line" users. **2:** Synology claimed their SMB implementation is proprietary, and do not provide any (useful) documentation on the interface. I *suspect* that Synology's implementation is not *that* far off mainstream, but after some trial-and-error, I'm still having *"permissions issues"*. Also, the mount.cifs manual has many options whose purpose and effect are vague to me. Are there any Linux tools available that can help identify how the various options and parameters in mount.cifs affect permissions as seen from the Linux client's perspective? I'd like to eliminate as much of the *trial-and-error* as possible. I'm interested in using SMB instead of NFS because I've heard more negatives on NFS than I have SMB. I have created the users on the Synology side and added them to the SMB config there. #### EDIT: 2022-07-12; More reading, findings The *variables* which seem to be in play are: 1. the state of the Linux implementation of the ["Unix Extensions"](https://wiki.samba.org/index.php/UNIX_Extensions) to SMB, and the version on my client machine 2. the state of the server's (Synology's) implementation of SMB/Samba 3. the state of the server's (Synology's) implementation of the "Unix Extensions" In an effort to improve the quality of this question, I've attempted to define these variables in the context of my question: 1. Re the state of the Linux implementation of the "Unix Extensions":

$ mount.cifs --version
   mount.cifs version: 6.11
   # NOTE1: Unix Extensions are enabled by default per man mount.cifs 
   # NOTE2: see also 'modinfo cifs'

2. Re server (Synology) version of SMB/Samba:

$ ssh admin@SynologyNAS-1
   /$ samba --version
   Version 4.10.18 
   /$ uname -srm
   Linux 4.4.180+ x86_64

3. Re server (Synology) version of the "Unix Extensions" ***I'm at a loss on how to do this, so I tried smbclient:***

$ smbclient \\\\SynologyNAS\\rpi_share -U=pi
   Enter WORKGROUP\pi's password:
   Try "help" to get a list of possible commands.
   smb: \> help
   ?              allinfo        altname        archive        backup
   blocksize      cancel         case_sensitive cd             chmod
   chown          close          del            deltree        dir
   du             echo           exit           get            getfacl
   geteas         hardlink       help           history        iosize
   lcd            link           lock           lowercase      ls
   l              mask           md             mget           mkdir
   more           mput           newer          notify         open
   posix          posix_encrypt  posix_open     posix_mkdir    posix_rmdir
   posix_unlink   posix_whoami   print          prompt         put
   pwd            q              queue          quit           readlink
   rd             recurse        reget          rename         reput
   rm             rmdir          showacls       setea          setmode
   scopy          stat           symlink        tar            tarmode
   timeout        translate      unlock         volume         vuid
   wdel           logon          listconnect    showconnect    tcon
   tdis           tid            utimes         logoff         ..
   !
   smb: \> ? posix
   HELP posix:
   	   turn on all POSIX capabilities
   
   smb: \> posix
   Server doesn't support UNIX CIFS extensions.
   smb: \> ? chmod
   HELP chmod:
	     chmod a file using UNIX permission
   
   smb: \> chmod test-touch-4B.txt 666
   Server doesn't support UNIX CIFS calls.
   ...

#### 2022-07-12; Conclusions & Revised Questions? The above results with smbclient ***suggest*** that with respect to SMB/CIFS, my client software is [*up to speed*](https://idioms.thefreedictionary.com/up+to+speed) , but my shiny new Synology NAS is far [*behind the curve*](https://idioms.thefreedictionary.com/behind+the+curve) . My original question now becomes, "Are these results accurate; is there a more conclusive or accurate method to determine the status of a product when the vendor refuses any information on it?" For those with similar questions, I can only offer this: >***In my case***: I mount using Synology user pi credentials. Doing so leaves my Linux user pi unable to write to the mounted share - despite the fact that Synology user pi had been given R&W privileges in the Synology DSM. I found that adding the uid=pi and gid=pi options to my mount -t cifs command, at least enabled the Linux user pi to write to the SMB share on the Synology server. ***Why*** this works I will have to leave for others to answer. ### Further Reading: 1. [The SMB UNIX Extensions Wiki](https://wiki.samba.org/index.php/UNIX_Extensions) 2. [CIFS VFS - Protocol extensions to the Common Internet File System for better POSIX file I/O semantics](https://www.samba.org/samba/CIFS_POSIX_extensions.html) 3. [A Search: what are the "Unix Extensions" for SMB/CIFS/Samba?](https://duckduckgo.com/?t=ffab&q=what+are+the+%22Unix+Extensions%22+for+SMB%2FCIFS%2FSamba&atb=v278-1&ia=web) . 4. [Samba version 4.3 or newer supports SMB 3.1.1](https://www.admin-magazine.com/Archive/2017/40/SMB-3.1.1-in-Windows-Server-2016) 5. [Linux cifs mailing list](http://vger.kernel.org/vger-lists.html#linux-cifs) 6. mount.cifs and mount.smb3 are *nearly* the same; ref man mount.cifs - which is also the manual for mount.smb3. 7. [The SMB3-Linux Wiki](https://wiki.samba.org/index.php/SMB3-Linux) 8. [Are SMB POSIX Extensions Same As SMB Unix Extensions?... *Apparently not*](https://snia.org/sites/default/files/SDC/2020/053-French-SMB3-POSIX-Extensions-Phase.pdf) 9. [CIFS Protocol Extensions Update, fm 2006 (This has been YEARS in the making)](https://download.samba.org/pub/samba/cifs-cvs/snia-developer-2006-cifs-extensions.pdf) 10. [A Tour through the CIFS Protocol Extensions and Linux CIFS client, fm. 2008](https://vdocument.in/a-tour-through-the-cifs-protocol-extensions-and-linux-cifs-almost-ntfscifs.html) . 11. [SMB3 POSIX Extensions Phase 2 ... what is next? (fm. 2020)](https://snia.org/sites/default/files/SDC/2020/053-French-SMB3-POSIX-Extensions-Phase.pdf) 12. [The video of #10 above](https://www.snia.org/educational-library/smb3-posix-extensions-phase-2-now-they-are-what-next-2020) 13. [The Linux kernel user’s and administrator’s guide » CIFS (note: more verbiage by Steve French)](https://www.kernel.org/doc/html/latest/admin-guide/cifs/index.html) 14. [What Is SMB Protocol and Why Is it a Security Concern?](https://cybersophia.net/articles/what-is/what-is-smb-protocol-and-why-is-it-a-security-concern/) 15. [Server Message Block - Wikipedia](https://en.wikipedia.org/wiki/Server_Message_Block)

I am trying to mount my new Synology DS923+ connected to my LAN switch with static DHCP reservation. OS: Linux Mint 22 Cinnamon based on Ubuntu 24.04. I already installed nfs-common package:

$ apt-cache policy nfs-common
nfs-common:
  Installed: 1:2.6.4-3ubuntu5
  Candidate: 1:2.6.4-3ubuntu5
  Version table:
 *** 1:2.6.4-3ubuntu5 500
        500 http://archive.ubuntu.com/ubuntu  noble/main amd64 Packages
        100 /var/lib/dpkg/status

First attempt in fstab:

192.168.0.77:/volume3/8TB /mnt/nas nfs vers=4.1,nofail,nouser,auto,rw,async,x-gvfs-show,x-gvfs-name=NAS 0 0

The above works only after boot. After login I must execute sudo mount -av, and it mounts. So far, I cannot figure out if it is even possible to mount automatically at boot. My laptop is not connected to WiFi, I use LAN instead. Since I am brand new to Synology NAS, please be patient with me, comment if you need any additional info. Thank you. **Note #1**: As suggested in comment, I added the bg option to that fstab line options. No change, sadly.

How to restart SSH daemon/service on Synology NAS with DSM 7.2? I already tried too many commands to remember them all, for example:

# synoservicectl --restart sshd

But none worked. Can anyone tell me what command to use on the latest to date version of DSM (7.2)? Thank you.

I'm on a NAS and had been running some YAMLs. I have a user ID johnG(1042) G(100) which was used for the YAML. There were some updates along, and I'm not sure how it happened but suddenly it changed to abc(1042) G(100). Now both names exist with the same ID and Group. I did not make the change knowingly and no one else has access to the NAS. Everything seems to be running, but I don't want to wait until there is an issue. How do I get rid of that second name to the same id?

I have a NAS RS816 - All my folders are encrypted, A user created a backup of a access file and then by accident deleted the file... I managed to recover the directory which contains 11 files. Each file has been named ECRYPTFS_FNEK_ENCRYPTED.F........etc I would like to decrypt each file using the password which was used to encrypt them, I also have the .key file How would i do this, I have tried the Sudo ecryptfs-recover-private but it does not file the files and when i try run the folder in terminal it still does not find the files Kind Regards

I want to use a command over ssh: ssh myuser@myhost mycommand but doing so I always get: sh: mycommand: command not found using following obviously works: ssh myuser@myhost /usr/local/bin/mycommand and i understand why: it's because the command is somehow executed over a non-login shell. Using the full command or any other parameters in my ssh command is not an option in my scenario. My command is executed by a script I cannot touch and worked on every host yet except this one. The host that's giving me the problem is a Synology NAS and the /etc/passwd setting for that *myuser* is: myuser:x:1048:100::/var/services/homes/myuser:/bin/sh ---------------------- Again: I can: - ssh as myuser into myhost - execute as myuser using the absolute path provided by *which mycommand* - execute mycommand (non absolute) when already on myhost (via ssh) I can't but want: - execute: ssh myuser@myhost mycommand (non absolute, no additional parameters)

I've installed Debian 12, and I'm wanting to map/mount a network drive (hosted on a Synology NAS). I see no reason for the 'no route' error as I can ping the Synology server's DNS name and IP address. Both respond just fine. Furthermore, I also have a separate Ubuntu workstation where this same line in the */etc/fstab* works:

//myserver.local/mynetworkdrive/ /mnt/mynetworkdrive/ cifs auto,vers=2.0,credentials=/home/myusername/.smbcredentials,iocharset=utf8,noperm 0 0

Doing a

dmesg

returns this bit of information:

: No dialect specified on mount. Default has changed to a more secure dialect, SMB2.1 or later (e.g. SMB3.1.1), from CIFS (SMB1). To use the less secure SMB1 dialect to access old servers which do not support SMB3.1.1 (or even SMB3 or SMB2.1) specify vers=1.0 on mount.

: Unable to determine destination address

However, the solution to this message appears to be already taken care of with the 'vers=2.0' directive I have in the fstab file (I've tried changing the version numbers with no success). Suggestions for the next steps to help resolve?

I want to mount a USB drive on my NAS synology Following those tutorials: https://askubuntu.com/questions/37767/how-to-access-a-usb-flash-drive-from-the-terminal https://linuxconfig.org/howto-mount-usb-drive-in-linux I could find the USB drive with the command:

$ blkid
/dev/mapper/vg1-volume_1: LABEL="2023.09.25-14:35:10 v64570" UUID="850bcccd-3982-43be-8857-ebd535c7ac92" UUID_SUB="998554af-d7c7-42de-b7fe-e0e153197119" TYPE="btrfs"
/dev/md0: LABEL="1.44.1-64570" UUID="da99711c-d604-4e26-ae5b-27d549704693" TYPE="ext4"
/dev/sdq1: LABEL="Samsung USB" UUID="64A5-F009" TYPE="exfat"

I Created a directory:

$ sudo mkdir /media/usb

and tried to mount the USB drive

$ sudo mount /dev/sdq1 /media/usb/
mount: /media/usb: operation permitted for root only.

I used the sudo command but the system still tells me that the operation is permitted for root only. What am I doing wrong?

I have a setup that worked fine (on Synology NAS), until a recent update. lp can apparently not print, even though the printer seems to exist okay:

$ lpstat -p -d
printer HP8210 is idle.  enabled since Fri 25 Feb 2022 11:35:36 AM CET
printer HP8740 is idle.  enabled since Mon 28 Feb 2022 10:28:47 AM CET

$ ls -l /opt/bin/lp 
-rwxr-xr-x 1 root root 18568 Oct  7  2018 /opt/bin/lp

$ /opt/bin/lp -d HP8740
/opt/bin/lp: No such file or directory

$ echo "foo" | /opt/bin/lp -d HP8740 2>&1
/opt/bin/lp: No such file or directory

I assume that "No such file or directory" means that something is incorrect regarding the printer/device configuration? It is reported here as an incorrect/inadequate output: https://bugzilla.redhat.com/show_bug.cgi?id=1811716 Looks lpr works fine, though. How can that be troubleshot? Edit: Added ls output, lpr output, and link to issue reported against lp on the output message.