0

I have one DELL Powervault ME4012 connected to two host servers (DELL PowerEdge R740 on Ubuntu 18.04) using 12 Gbps SAS HBAs. The ME4012 storage is configured as one virtual volume with RAID type ADAPT. The volume is mounted on both host servers (EXT4). When i write a file on the mounted volume from Host A, the file does not appear on the volume mounted on Host B. The file shows up on Host B Only after I un-mount and then re-mount the volume on Host B.

I have tried changing the virtual volume cache setting using ME4012 management interface from default "Write-back" to "Write-through" to no effect. So what else can i try to make the files written from Host A visible on Host B immediately.

Like if we open the same directory in two separate windows and create a new folder in window A, the same folder appears instantly on window B as well, because it is the same directory open in two separate windows. I expect the same to work across two servers because the underlaying directory/volume is still the same.

Am_M
  • 3
  • 2
  • Mounting a block device on several hosts simultaneously *requires a cluster filesystem*. What you likely want is a *file share* like NFS. – Zac67 Mar 09 '21 at 17:59

2 Answers2

1

You should never mount a simple EXT volume on two different hosts. You are going to cause all kinds of issues. If you need access to those files from multiple machines, connect them to a host and share them using SMB/NFS.

Bert
  • 2,863
  • 12
  • 13
1

You must not mount an ext4 volume concurrently on two machines. Not seeing data written on one host on the other host is one of the more harmless results. You will also see data corruption, one host overwriting data the other host has written, and worse.

If you want to access files concurrently from several hosts you need a network filesystem like NFS or SMB.

Tilman Schmidt
  • 4,101
  • 12
  • 27