Questions[readwrite](server)

I've a problem of random writing speed on a Lenovo X3650 M5 with ServeRAID M5210.

The server has seven 600GB SAS disks divided into two logical groups: a RAID1 (2 disks) and a RAID10 (4 disks)

The last disk is a global hot spare.

The RAID 10 has 500MB/s in seq. reads and 250 MB/s in seq. writes and it almost double the speed of the RAID 1 array as expected.

The problems rise during 4K write test with a result of less then 1 MB/S for both RAIDs in both writes and reads.

The logical virtual disks properties:

RAID 1:
Write Policy: Write Through
Read Policy: Always Read Ahead
IO Policy: Direct IO
Disk Cache Policy: Unchanged
Background Initialization: Enabled

RAID 10:
Write Policy: Write Through
Read Policy: Always Read Ahead
IO Policy: Direct IO
Disk Cache Policy: Disabled
Background Initialization: Enabled

The Server Profile:
SERVER---
    Server IP:               xxx.xxx.xxx.xxx
    Server Name:             XXX
    OS name:                 Windows Server 2012
    OS Version:              6.2
    OS Architecture:         x86_64
    Driver Name:             megasas2.sys
    Driver Version:          6.706.06.00
    Application Version:     MegaRAID Storage Manager - 15.03.01.00

HARDWARE---              
    Controller:              Controller0: ServeRAID M5210(Bus 21,Dev 0,Domain 0)
    Status:                  Optimal
    Firmware Package Version:24.7.0-0052
    Firmware Version:        4.270.00-4288
    BBU:                     NO
    Enclosure(s):            1
    Drive(s):                7
    Virtual Drive(s):        2

Enclosures---
    PRODUCT NAME             TYPE                     STATUS                   
    Backplane                Sgpio                    OK                       

Drives---
    CONNECTOR                PRODUCT ID               VENDOR ID                STATE                    DISK TYPE                CAPACITY                 POWER STATE              
    Port 4 - 7               AL13SEB600               LENOVO-X                 Online                   SAS                      557.861 GB               On                                                
    Port 4 - 7               AL13SEB600               LENOVO-X                 Online                   SAS                      557.861 GB               On                                                
    Port 4 - 7               AL13SEB600               LENOVO-X                 Online                   SAS                      557.861 GB               On                                                
    Port 4 - 7               AL13SEB600               LENOVO-X                 Online                   SAS                      557.861 GB               On                                                
    Port 0 - 3               AL13SEB600               LENOVO-X                 Online                   SAS                      557.861 GB               On                                                
    Port 0 - 3               AL13SEB600               LENOVO-X                 Online                   SAS                      557.861 GB               On                                                
    Port 0 - 3               AL13SEB600               LENOVO-X                 Global Hot Spare         SAS                      557.861 GB               On                                                

Virtual Drive(s):---
    TARGET ID                NAME                     CAPACITY                 STATE                    RAID LEVEL               MegaRAID RECOVERY        
    0                        -                        557.861 GB               Optimal                  RAID  1                  NO                                                
    3                        VD_1                     1.090 TB                 Optimal                  RAID  10                 NO  

Anyone has any advice?

because of my unanswered question : qemu snapshot exclude device i decided to use NFSv3 for the VM to handle user data. Because of slow performance of BTRFS after maintance-tasks i use now zfs Raid1 Version: buster-backports 0.8.3-1 on the Debian Host.

When I copy data on the host there is no performance problem.

BUT: the performance via NFS is exorbitant slow; in the beginning for both write and read with 10 and 40 MB/s. After some Tuning (i think it was NFS with async) i got the writes to ~80 MB/s. Thats enough for me. The reads stayed at 20 MB/s per device, yet.

Any ideas what to test? I'm new to zfs and NFS.

Host: Debian 10
VM: Debian 10

NFS: Host: /exports/ordner 192.168.4.0/24(rw,no_subtree_check)
client: .....nfs local_lock=all,vers=3,rw,user,intr,retry=1,async,nodev,auto,nosuid,noexec,retrans=1,noatime,nodiratime

ZFS dataset:

Volume with:
....create -o ashift=12 zfs-pool ....mirror
sync=default

zfs set compression=off zfs-pool
zfs set xattr=sa zfs-pool
zfs set dnodesize=auto zfs-pool/vol
zfs set recordsize=1M zfs-pool/vol
zfs set atime=off zfs-pool/vol

zfs-mod-tune:

options zfs zfs_prefetch_disable=1
options zfs_vdev_async_read_max_active=1
options zfs_vdev_sync_read_max_active=128 (also 1 tested)
options zfs_vdev_sync_read_min_active=1

Can u give an advice?

Situation:

We are using a Nexenta appliance for NFS file serving (nfs v3). We are sharing a path for anonymous read/write access.

We have a Linux host we would like to mount that exported read/write share and also allow anonymous read/write access to that mounted share on that client machine. Unfortunately, what ends up happening is that root can write to the share, but unprivileged users cannot.

Using the following methods to mount the share:

# mount -t nfs -o rw 10:10:xx:xx:/path/to/share /mnt/mounted_path
# mount -t nfs -o rw,users 10:10:xx:xx:/path/to/share /mnt/mounted_path
# mount.nfs 10:10:xx:xx:/path/to/share /mnt/mounted_path -o rw

We have specific user we intend to use for the anonymous usage on the share. So I attempted to mount the volume as that user:

# su - shared_user
$ sudo mount.nfs 10:10:xx:xx:/path/to/share /mnt/mounted_path -w -o user=shared_user,rw
mount.nfs: an incorrect mount option was specified

Went and did some reading: http://nfs.sourceforge.net/nfs-howto/ar01s06.html.

Decided to give the following a try which give the proceeding errors when attempting to mount:

# mount -t nfs -orw,no_root_squash 10:10:xx:xx:/path/to/share /mnt/mounted_path 
mount.nfs: an incorrect mount option was specified
# mount -t nfs -orw,nroot_squash 10:10:xx:xx:/path/to/share /mnt/mounted_path  # for grins and giggles.
mount.nfs: an incorrect mount option was specified
$ sudo mount.nfs 10:10:xx:xx:/path/to/share /mnt/mounted_path -w -o user=shared_user,rw,no_root_squash
mount.nfs: an incorrect mount option was specified

Am I just SOL or is there something I'm fundamentally missing here? Is this a holy grail I'm attempting to find? I have never heavily used NFS so I'm at a bit of a loss here, now. TIA!

Installed Cygwin's NFS server. It works. But I can't make it allow writing to the filesystem. Why does it fail?

Server:

$ cat /etc/exports
#/ 10.99.98.2(rw,no_root_squash)
/cygdrive/c/foranevia *(rw,no_squash_root,anon_uid=0,anon_gid=0,no_subtree_check)

Client:

root@vi-notebook:/mnt# mount wpc:/cygdrive/c/foranevia nfs
root@vi-notebook:/mnt# mkdir nfs/qqq
mkdir: cannot create directory `nfs/qqq': Read-only file system

Update: Fixed configuration line to /cygdrive/c/foranevia *(rw,no_root_squash) and now it seems to work, although not all hosts can mount until I explicitly list them in /etc/exports.

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