topic Files Deleted in MSA Storage

Files Deleted

create share — Fri, 20 Mar 2015 02:28:17 GMT

Hi!

After restarting the server where HP MSA 1000 is connected the screen was showing "resetting security on the files" before loading windows. We immediately restarted the server and after windows loaded we found many of our files and fodlers were deleted from the storage and the security for all foders was reset and only admin was left under ntfs permissions.

Windows 2008 R2

Any suggestions?

P.S. This thread has been moevd from General to Storage Area Networks (SAN) (Small and Medium Business). - Hp Forum Moderator

Re: Files Deleted

Johan Guldmyr — Wed, 02 Jan 2013 08:42:03 GMT

Hi!

This sounds like an Windows question. The MSA just provides storage - what happens on it is up to the OS. Perhaps you've gotten virus or changed something before the reboot?

Re: Files Deleted

Matti_Kurkela — Wed, 02 Jan 2013 08:52:59 GMT

It sounds like your disk was corrupted and Windows was probably running CHDSK at boot time to try and fix it.

If you forced a server restart in the middle of the CHKDSK, that may have made the problem worse.

This is exactly why you are supposed to take backups of your data.

Just restore the missing files from the latest backup, if you have it.

If you don't have a backup and the data was critical, don't write anything to that disk/LUN, and contact data recovery professionals.

Determining the root cause of the disk corruption may be difficult. Did the server crash before the first restart you mentioned? Check the event logs to see if there are any crash reports or other signs of trouble.

Re: Files Deleted

create share — Wed, 02 Jan 2013 17:04:50 GMT

The server is running fine. It did not crash. I need to ask one more thing. Before it hapenned the storage was connected to two servers and the same drives (Luns) were configured on both servers by iscsi initiator. There was no clustering between servers for hp storage. One thing I noted that updating files on storage from one server were not immediately shown by the luns on the second server. I had to restart the server to get the updated files on the 2nd server. Can this cause any problem if you just connect the storage through iscsi initiator on two servers without checking the proper way to connect them?

Thanks.

Re: Files Deleted

Johan Guldmyr — Wed, 02 Jan 2013 18:18:50 GMT

There was a post by Matti earlier today about that. You need to use a clustering service / filesystem if you have a shared disk between two servers.

http://h30499.www3.hp.com/t5/System-Administration/Redhat-6-2-Without-Cluster-Shared-LUNS-READ-WRITE/m-p/5918635#M54026

Re: Files Deleted

Matti_Kurkela — Thu, 03 Jan 2013 08:16:18 GMT

>One thing I noted that updating files on storage from one server were not immediately shown by the luns on the second server. I had to restart the server to get the updated files on the 2nd server.

After the second server had read the directory metadata once, it held the metadata in its cache. Since nothing informed the second server that the first one had made some changes to the disk, the second server assumed that its cached copy was still good. Any write operation to that directory from the second server could have replaced the directory metadata with the version from the second server, effectively overwriting the changes made by the first server.

This can happen anywhere and everywhere on the shared disk:

with the data in your files, so your files will be corrupted
with the directory metadata, so filenames and permissions will be corrupted
with the block allocation metadata, so the filesystem's idea of what blocks are free and what are in use will get distorted... and that will cause yet more situations where important data or metadata can get overwritten

Once you realize the full implications of this, you'll understand why sharing a LUN with only storage-level protocols won't work with normal non-cluster filesystems.

This is true for all storage-level protocols that can present a disk/LUN to two or more hosts simultaneously:

differential SCSI
FibreChannel
iSCSI
ATA over Ethernet
FCOE
etc.

There are other ways to share a filesystem to multiple hosts. Things like NFS and CIFS (=Windows file sharing) can certainly do it... but in both cases, the actual disk access is done by a single system at a time. This system can be either a normal server or a dedicated NAS device.