- Community Home
- >
- Servers and Operating Systems
- >
- Operating Systems
- >
- Operating System - HP-UX
- >
- Re: Mirror/UX, third mirror, split, backup and res...
Categories
Company
Local Language
Forums
Discussions
Forums
- Data Protection and Retention
- Entry Storage Systems
- Legacy
- Midrange and Enterprise Storage
- Storage Networking
- HPE Nimble Storage
Discussions
Discussions
Discussions
Forums
Forums
Discussions
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
- BladeSystem Infrastructure and Application Solutions
- Appliance Servers
- Alpha Servers
- BackOffice Products
- Internet Products
- HPE 9000 and HPE e3000 Servers
- Networking
- Netservers
- Secure OS Software for Linux
- Server Management (Insight Manager 7)
- Windows Server 2003
- Operating System - Tru64 Unix
- ProLiant Deployment and Provisioning
- Linux-Based Community / Regional
- Microsoft System Center Integration
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Community
Resources
Forums
Blogs
- Subscribe to RSS Feed
- Mark Topic as New
- Mark Topic as Read
- Float this Topic for Current User
- Bookmark
- Subscribe
- Printer Friendly Page
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО05-11-2004 02:30 AM
тАО05-11-2004 02:30 AM
Mirror/UX, third mirror, split, backup and resync
I want to have a set of mirrored logical volumes backed up to tape without having to wait for the backup to complete. The obvious way to achieve this is to have a third mirror copy, which can be split from the other two and the third copy can be backed up whilst the originals can be accessed and updated (this might be a database for example). Once the backup is complete, resyncronise the copy.
My questions are:
1) Are there any figures/statistics available that might give some clue has to how long the resync process will take?
2) Also what performance impact would the resync have on the 'original' copies?
I appreciate that it is very dependent on the hardware being used (to be decided) and the amount of data (probably around 100GB)...
Many thanks
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО05-11-2004 02:39 AM
тАО05-11-2004 02:39 AM
Re: Mirror/UX, third mirror, split, backup and resync
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО05-11-2004 02:41 AM
тАО05-11-2004 02:41 AM
Re: Mirror/UX, third mirror, split, backup and resync
2) The resync's impact can be noticable especially during times of busy activity; of course, if the disks are that busy running the application during normal periods then the application was probably not written very well in the first place.
Let me suggest a Plan B. Rather than using lvsplit use the OnlineJFS option snapof= to create a snapshot of the original filesystem. The snapshot takes only seconds on very large filesystems and you don't take the large performance hit of resyncing. There is no free lunch because the IO hit is spread across the time when the database is in normal use while the snapshot is in effect. The hit is rather small because only THE FIRST TIME that a given block is changed in the original filesystem must that block first be copied to the snapshot buffer. The snapshot is actually a composite of the original filesystem's unchanged blocks plus a version of the changed blocks as they were when the snapshot mount was created.
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО05-11-2004 02:48 AM
тАО05-11-2004 02:48 AM
Re: Mirror/UX, third mirror, split, backup and resync
Are there any threads that go into it in more detail?
Thanks again...
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО05-11-2004 02:48 AM
тАО05-11-2004 02:48 AM
Re: Mirror/UX, third mirror, split, backup and resync
We used to use this process ( with lvsplit/lvmerge) to back up a 30GB database, and it had no noticeable impact during the process. The split took up to 30 seconds, and the merge 10-15 seconds.
Things to consider;
1) When you split the mirror, any applications should be down to ensure that the copy is not corrupted (due to files being in use). For the resync, your applications can remain active.
2) You will need to fsck the split filesystems to be able to mount them and back up the data.
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО05-11-2004 02:50 AM
тАО05-11-2004 02:50 AM
Re: Mirror/UX, third mirror, split, backup and resync
2)I expect the peformance impact to be noticeable, however I've done this during the day many times and never had a complaint.
I would suggest another method to do this with no(little) impact on peformance.
Online JFS snapshot.
Leave the mirror at two copies. Allocate the logical volume that was the second mirror as a "hot" backup section. It usually needs about one fifth of the disk space of a full mirror.
make a mountpoint for this purpose
mkdir /snapshot
# lets call the logical volume snapshot
# lets call the original logical volume mountpoint /data
mount -F vxfs -o snapof=/dev/vg01/lvol1 /dev/vg01/snapshot /snapshot
You run your backup against the original mountpoint /data
What happens is that while the snapshot is open, the kernel takes all block changes and stores them in the /snapshot mount logical volume snapshot.
Its just like a cold backup. You can down the oracle database, set the snapshot and bring it right back up.
To close the snapshot:
umount /snaphot
The block changes are moved back where they really happened, data.
Slick, fast, reliable.
SEP
Owner of ISN Corporation
http://isnamerica.com
http://hpuxconsulting.com
Sponsor: http://hpux.ws
Twitter: http://twitter.com/hpuxlinux
Founder http://newdatacloud.com
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО05-11-2004 04:46 AM
тАО05-11-2004 04:46 AM
Re: Mirror/UX, third mirror, split, backup and resync
Timefinder BCV/SRDF from EMC on EMC symetrix/DMX storage .
buisness copy from HP on XP storage
will do the same what you are aiming for .
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО05-12-2004 04:35 AM
тАО05-12-2004 04:35 AM