7.3.1 Snapshot Backups - how & do they work?

Hi DevNetters -
We're prepping to do an installation of 7.3.1 on a Linux VM.

Having figured out a working method to snapshot backup the 6.7.1 repository on Solaris in the past, I'm interested in using the new snapshot backup capability of 7.3.1. It might save us some effort.

The doco on the new feature is slim (go figure..) Have any of you implemented this and have some comments on how you're utilizing it?

Many thanks,
Wally Box
Nike, Inc.

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Adam Stoller

Hi DevNetters -
We're prepping to do an installation of 7.3.1 on a Linux VM.

Having figured out a working method to snapshot backup the 6.7.1 repository on Solaris in the past, I'm interested in using the new snapshot backup capability of 7.3.1. It might save us some effort.

The doco on the new feature is slim (go figure..) Have any of you implemented this and have some comments on how you're utilizing it?

Many thanks,
Wally Box
Nike, Inc.

I'm not positive but I think snapshotting of the backing store only applies if you have your backing store on a NAS device - I don't think it matters at all what OS your server is running on, just the location of the backing store - because (and this is a semi-educated guess) TeamSite is probably only calling some NetApp's code to perform the snapshot.

Migrateduser

Thanks Ghoti -

They cover that somewhat in the doco by saying what type of storage it needs to be on. And they let us know where within iw.cfg an entry needs to be made to enable it.

But I can't yet find any info on:
- how it is invoked (via the Admin UI? Can it be scheduled to coincide with a tape backup system?)
- how it is any different than us just invoking the native snapshot capabilities outside TeamSite.
- if there are additional space requirements.
- if there is any dependency between the repository and the back-end database that might require a parallel backup of both (there was no db in 6.7.1)

I've opened a support case as well. I'll try to remember to post any findings I come up with here.

Wally

ukscottallen

Hi Wally,

Was wondering if you managed to find a solution for this?

I am also interested in snapshotting our iw-store volume. We're on TS741, RHEL6.4 and iw-store located on a SAN. Im am aware of this new setting;

[iwserver]
sync_content_writes=on

which allows snapshot's to be taken without using an iwfreeze, but am trying to understand how to best do the snapshot.

We have a TS Prod server and a TSDR (Disaster Recovery) server (in different data centers). TS DR is a cold-standby so TeamSite processes are not running on here - we just start them up if we need to use it. At the moment, we still freeze the backing store every evening at 11:50pm on PRD, then rsync the iw-store to TS DR. Therefore if we get a crash on TS PRD, the next day at say 3pm, and it takes time to fix etc, and we want to switch our users to TS DR, we have potentially lost all the content editors work from 9am - 3pm.

We would really like to take a snapshot of iw-store in prd at regualar intervals (say every 30 mins), without putting prd into freeze/read only mode, so that this snapshot of iw-store could then be installed on TS DR server, thus proventing a big loss of content in case of a switch to DR.

I was wondering if it would be possible to create the snapshot using LVM? Or does the snapshot have to be created at SAN level?

Any info you can provide on your solution, if you find one, would be greatly appreciated.

Thanks a lot

Kind Regards

Scott

Rick Poulin

The "snapshot" support introduced in 7.3 is not really a feature of TeamSite itself. What they're saying is that if you host the content store on a NAS, and it has the capability to "queue" pending write operations while it takes a snapshot, then the product will support this. The entire process happens on your NAS, not in TS.

Whether you'll be able to do this in such a tight interval really depends on your NAS and the size of your content store.

ukscottallen

Thx for the reply

Yes i realise the snapshot can not be taken with Teamsite.

We are using TS on RHEL VM. My question was more if we can use Logical Volume Manager (LVM) on RHEL to take a snapshot of the iw-store volume and will it work be supported? or does it have to be done at the SAN level?
Snapshotting should be relatively quick to do.

We have our LUN from SAN presented to ESX host, which then is sliced into virtual HDDs assigned to VMs - some more details below

Do you know if the LVM snapshot works? i.e. can we do something like below?

cat /usr/local/bin/LVM_backup.sh
#!/bin/bash
# lvm snapshot backup

# create a snapshot volume
lvcreate --size 500m --snapshot --name snap /dev/mapper/appsvg-iwstorelv

# mount snapshot volume
mount /dev/mapper/appsvg-snap /snap/

# do a backup to another server
rsync -avz /snap/ teamsite_DR_server:/apps/cms/iw-store

# un-mount snapshot volume
umount /snap/

# remove snapshot volume
lvremove /dev/mapper/appsvg-snap -f
[root]# 11:14
bash script from test VM

We have for example on our lab server these volume groups / logical volumes (including iw-store);
[root]# vgs
VG     #PV #LV #SN Attr   VSize   VFree
appsvg   1   5   0 wz--n- 160.00g 45.00g
rootvg   1   7   0 wz--n- 31.72g 10.72g

[root]# lvs
LV            VG     Attr      LSize Pool Origin Data% Move Log Cpy%Sync Convert
appslv        appsvg -wi-ao--- 5.00g
cmslogslv     appsvg -wi-ao--- 10.00g
cmslv         appsvg -wi-ao--- 30.00g
iwstorelv     appsvg -wi-ao--- 50.00g
searchstorelv appsvg -wi-ao--- 20.00g
datalv        rootvg -wi-ao--- 2.00g
logslv        rootvg -wi-ao--- 2.00g
optlv         rootvg -wi-ao--- 1.00g
rootlv        rootvg -wi-ao--- 3.00g
swaplv        rootvg -wi-ao--- 4.00g
tmplv         rootvg -wi-ao--- 5.00g
varlv         rootvg -wi-ao--- 4.00g

/dev/mapper/appsvg-iwstorelv
51606140 474872 48509828 1% /apps/cms/iw-store

Rick Poulin

I mean, the docs specifically state:

The feature requires the backing store to be on a SAN or NAS with snapshot capabilities. This feature is not a supported when the backing store is on a regular local disk.

so your LVM approach is technically not supported, but it wouldn't hurt for you to ask the question to HP support directly. Can't say I've tried that approach myself.

nipper

The problem you will have is that it may very well work *most* of the time. So you could have abackup that is valid *most* of the time.

Maybe that is OK, esp if you are really doing it hourly (though you must have a fairly small backingstore (mine is currently 1.2 TB).

Assuming HP tells you non-supported. Try it and then reload it. Several times. Especially take a snapshot under load and restore it. Run iwfsck before you start and when you restore it.