Login or Register to Ask a Question and Join Our Community

Sponsored Content
Full Discussion: Faster way: SAN hd to SAN hd copying
Special Forums Hardware Filesystems, Disks and Memory Faster way: SAN hd to SAN hd copying Post 303007674 by rbatte1 on Monday 20th of November 2017 05:57:48 AM
Old 11-20-2017
When you say 'a faster way', are you trying to move the data from one SAN to another, so that you can detach the original and you need to make the offline time as short as possible?

If your disk is LVM, then you might be better to proceed like this:-
  • Get the new LUN assigned and re-scan to pick it up if necessary
  • Make the whole new LUN into an LVM Physical Volume with pvcreate
  • Add the PV into the volume group containing the data you want to move
  • Alter the logical volume holding your filesystem/data to have two copies, specifying the new PV as the target. This will take a long time, but the applications remain available because the data is still accessible.
  • Verify that the logical volume has no errors reported.
  • Alter the logical volume to have just a single copy, specifying the old SAN device to be removed
  • Repeat the mirror/drop for as many logical volumes as you need to move to completely free the old PV
  • Remove the old PV from the volume group
  • Detach the old LUN from the OS
  • Detach the old LUN from the SAN side

Using the tools in the OS rather than trying to do the work yourself should be a lot neater. The logical volume is moved, but the filesystem has no idea about it, so all the files remain exactly as they were and your applications, backups or whatever can happily carry on.

I prefer to add a mirror to the new device rather than just execute a move for large logical volumes just in case there are any issues in the process. You don't destroy the original so you can always drop the new copy and start again.


Have I missed the point and waffled on about something irrelevant? My apologies if I have, but I hope that this helps. If you are looking to make another copy to be used separately, then we might be able to use LVM to do that too, but that would be a copy at a fixed point in time that would then go out of date with respect to the original as either is changed (you suggest that there are many concurrent processes working on it)


Anyway, I hope that this helps. Please feel free to correct me if I'm way off target.


Kind regards,
Robin
 

10 More Discussions You Might Find Interesting

1. UNIX for Dummies Questions & Answers

what is SAN

Hello all, I have looked at the entire posting that have SAN in it and I'm still fuzzy on how SAN works. I understand that every disk array can be access from any server that needs it, but is there software that is install or NFS mount type situation. One post stated that if your format command... (7 Replies)
Discussion started by: larry
7 Replies

2. AIX

San:

hi We have 2 AIX nodes running with HACMP and all of them connected to SAN, Our shared storage is shark; I need to create shared volume group and I need the HACMP take a ware of it. Regards (1 Reply)
Discussion started by: h2aix
1 Replies

3. HP-UX

SAN migration

Hi, I'm going to be involved in a migration of SAN islands to one big SAN. I've not worked with SANs before and I'm not sure how to approach this. I suspect the disk devices on the HP servers are going to change, when the EVA's and servers are plugged into this new Cisco 9509 switch. Any... (0 Replies)
Discussion started by: Hils
0 Replies

4. Solaris

Connecting to SAN

I am about to attempt to connect my sun 280R boxes to a EMC SAN. I have Qlogic cards that came from Sun. I am going to load traffic manager, navisphere client. what else do i need, sun foundation suite ro somehting? This is the first time ive ever connected to a SAN. any help would be... (3 Replies)
Discussion started by: BG_JrAdmin
3 Replies

5. Solaris

Thoughts/experiences of SAN attaching V880 to EMC SAN

Hi everyone, I wonder if I can canvas any opinions or thoughts (good or bad) on SAN attaching a SUN V880/490 to an EMC Clarion SAN? At the moment the 880 is using 12 internal FC-AL disks as a db server and seems to be doing a pretty good job. It is not I/O, CPU or Memory constrained and the... (2 Replies)
Discussion started by: si_linux
2 Replies

6. AIX

SAN error

Dera all I have error repeating for two day, when I checked the error log by errpt command: ------------------------------------------------------------------------ LABEL: SC_DISK_ERR2 IDENTIFIER: 79B0DF89 Date/Time: Wed Oct 31 02:41:36 SAUS Sequence Number: 9000... (1 Reply)
Discussion started by: magasem
1 Replies

7. Linux

Linux on SAN

Hello everyone. I was wondering if there is a way to increase the size on the LUN on a SAN and make the Linux kernel understand the changes without restarting? In the past it has always been rebooted to see the new values but im sure that there is a way now for the lvm to see the Free PE in... (8 Replies)
Discussion started by: d_ark
8 Replies

8. UNIX for Dummies Questions & Answers

Storage from SAN

hi guys I installed Centos 5.5 (local disk). I am using 2 HBAs Now I mapped 5 LUNs from a Storage. I will be using LVM just to test I assigned a LUN I've read I have to use multipath to avoid my Centos see the LUN twice I enabled mdmpd and multipathd... something else I should do? ... (8 Replies)
Discussion started by: kopper
8 Replies

9. AIX

New to San Storage

Can anyone recommend a good book on san storage basics and how it communicates with an AIX server? (1 Reply)
Discussion started by: NycUnxer
1 Replies

10. AIX

IBM SAN TO SAN Mirroring

Has anyone tried SAN to SAN mirroring on IBM DS SAN Storage. DS5020 mentions Enhanced Remote Mirror to multi-LUN applications I wonder if Oracle High availibility can be setup using Remote Mirror option of SAN ? (1 Reply)
Discussion started by: filosophizer
1 Replies

LEARN ABOUT SUSE

vgreduce

VGREDUCE(8)						      System Manager's Manual						       VGREDUCE(8)

NAME

       vgreduce - reduce a volume group

SYNOPSIS

       vgreduce  [-a|--all] [-A|--autobackup y|n] [-d|--debug] [-h|-?|--help] [--removemissing] [-t|--test] [-v|--verbose] VolumeGroupName [Physi-
       calVolumePath...]

DESCRIPTION

       vgreduce allows you to remove one or more unused physical volumes from a volume group.

OPTIONS

       See lvm for common options.

       -a, --all
	      Removes all empty physical volumes if none are given on command line.

       --removemissing
	      Removes all missing physical volumes from the volume group, if there are no logical volumes allocated on those. This resumes  normal
	      operation of the volume group (new logical volumes may again be created, changed and so on).

	      If this is not possible (there are logical volumes referencing the missing physical volumes) and you cannot or do not want to remove
	      them manually, you can run this option with --force to have vgreduce remove any partial LVs.

	      Any logical volumes and dependent snapshots that were partly on the missing disks get removed completely. This includes those  parts
	      that lie on disks that are still present.

	      If your logical volumes spanned several disks including the ones that are lost, you might want to try to salvage data first by acti-
	      vating your logical volumes with --partial as described in lvm (8).

SEE ALSO

       lvm(8), vgextend(8)

Sistina Software UK					 LVM TOOLS 2.02.67(2) (2010-06-04)					       VGREDUCE(8)
All times are GMT -4. The time now is 06:48 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy