GFS 有人用过吗？性能表现怎么样？！

成长中

现在centos 上面 各个版本的 gfs 都可以下到

包括 redhat3 ,redhat4 ,的，目前正在研究 redhat4，好像4 有很多硬件限制。

bob_zhang2004

我现在在用iSCSI的opensource ：iSCSI Enterprise Target 。
当我把target端一个harddisk的 分区share出来时候，我发现如果就是一个Initiator 连接，mount并操作 这个分区 ，是没有问题。
但是如果是两个用户，比如操作同一个目录，第二个连接的initiator所写的数据根本保留不下来（当两个initiator都dis－connect ，然后重新连接，发现第二个initiator写的数据丢失了）

订阅 iSCSI Enterprise Target的mailing list ， 开发者说 GFS 看来可以。
他的mail如下：

iSCSI really is just the handling of data blocks to and from the hard disk. Think of it as an extension of the hard disk that goes across the wire.

If you have multiple servers connected to a volume it is exactly like having a shared SCSI bus between multiple hosts. There is nothing in the SCSI controllers to prevent you from corrupting your shared volumes. This kind of control needs to come from the operating system. The OS needs to know the volume is shared and either a special file-system or special handling needs to take place. I don't know of a shared file-system in Windows, but Microsoft Cluster Services allow one server at a time access to a shared volume using SCSI Reserve/Release.

iSCSI must follow the SCSI protocol and the only function available to aid in shared access is SCSI RESERVE/RELEASE, which is a form of mutex.

-Ross




--------------------------------------------------------------------------------
From: Bob Zhang [mailto:bob_zhang2004@163.com]
Sent: Tuesday, January 30, 2007 9:12 PM
To: Scott Kaelin; Ross S. W. Walker; blackmagic02881@gmail.com
Cc: blackmagic02881@gmail.com; iscsitarget-devel@lists.sourceforge.net
Subject: Re: [Iscsitarget-devel] about mutex between multi-users to write a same target disk ? for example , multi-users write a same directory of /dev/hdb1 at the same time


thanks very much ! But I can't open this page : http://en.wikipedia.org/wiki/ISCSI

Ross and Ming ,do you have any review ?

By the way , now I am reading the code of IET , can I find a good development document ?

Thanks ahead ,

Best Regards ,
Bob

----- Original Message -----
From: Scott Kaelin
To: Bob Zhang
Cc: blackmagic02881@gmail.com ; iscsitarget-devel@lists.sourceforge.net
Sent: Monday, January 29, 2007 9:30 PM
Subject: Re: [Iscsitarget-devel] about mutex between multi-users to write a same target disk ? for example , multi-users write a same directory of /dev/hdb1 at the same time


Bob,
It is my understanding that in order to mount the same target device on multiple initiator machines the file system should be cluster aware, i.e GFS or it's microsoft counterpart. When multiple initiators mount the same device, except in read-only mounts, the device will experience corruption. See http://en.wikipedia.org/wiki/ISCSI specifically the 'Storage Device' section for why this happens.

Cheers,

Scott Kaelin
Sitrof Technologies


－－有人用过 iSCSI + GFS 吗？