-----Original Message----- From: centos-bounces@centos.org [mailto:centos-bounces@centos.org] On Behalf Of John R Pierce Sent: Friday, February 23, 2007 11:41 AM To: CentOS mailing list Subject: Re: [CentOS] iSCSI, windows, & local linux access
Andrew Cotter wrote:
Hello all,
I am looking to build a larger array (6TB) using CentOS 4.4
to archive
data to. We want to have the Windows server mount this array as a local drive so we were looking at iSCSI to do it. I have
played with
it in the past and gotten it to work in this combo, but I have a question about access to the data on the local (Centos) machine.
If I understand correctly, when I mount the device on
windows, I need
to format the array in a format that Windows (2003 server) can understand. Also, iSCSI only allows you to mount the
array on one
server at a time. Once I do that and write files to this array, is there anyway to access those files from the local machine
(Centos)? I
may want to do things like rsync to another location, copy files to another removable SATA disk, or just plain delete something.
Is it a choice of the OS so both windows and linux can read it? Little help with which one then. I know NTFS is still
somewhat in its
infancy.
if its mounted as a block device, nothing else should touch it, read OR write. block devices are NOT sharable, with the exception of specialized filesystems like GFS or IBrix Fusion Even a read only access would have issues with metadata consistency, if windows is updating a directory or MFT or whatever, linux could see stale/mixed data and would just throw up
Technically yes, if the volume has long periods of no activity though there should be no problem in taking a snapshot and mounting that. Understand that if the volume is being actively used by a backup process the data contained therein will not be consistent, but it will not harm the production volume, just the snapshot will not be considered prime.
the only 'safe' way to do it would be for the windows machine to share the logical file system, and have the linux system access it as a smbmount via samba. or use replication running on the windows server (rsync from mingw, etc)
Yes sharing it and mounting it back via CIFS is more reliable for a highly active volume, but if you plan to then copy-out data over the network it will slow things down to a crawl.
Windows 2003 server has its own snapshotting capabilities, btw.
Which IMHO are crap. If it's backup jobs that are accessed during a run, but otherwise sit there unused, then you can snapshot them off LVM fairly safely.
-Ross
______________________________________________________________________ This e-mail, and any attachments thereto, is intended only for use by the addressee(s) named herein and may contain legally privileged and/or confidential information. If you are not the intended recipient of this e-mail, you are hereby notified that any dissemination, distribution or copying of this e-mail, and any attachments thereto, is strictly prohibited. If you have received this e-mail in error, please immediately notify the sender and permanently delete the original and any copy or printout thereof.