sara2000
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Running VNX on snapshot
Hi all,
I know running VM on a snapshot is not good in terms of performance and disk space. I have seen a client who runs a VM with a snapshot for a long time (two months so far). The reason they keep the snapshot because the application breaks when the backup runs every day so they decided to keep the snapshot. I can not find any documental evidence to giving them that if you run a VM with snapshot more 74 hours then chances the will break. As far as my client concern It is running ok and they want to keep it as it is. Will they get a nasty surprise one day keeping the snapshot?
What would happen if you run the VM with a snapshot?
I know running VM on a snapshot is not good in terms of performance and disk space. I have seen a client who runs a VM with a snapshot for a long time (two months so far). The reason they keep the snapshot because the application breaks when the backup runs every day so they decided to keep the snapshot. I can not find any documental evidence to giving them that if you run a VM with snapshot more 74 hours then chances the will break. As far as my client concern It is running ok and they want to keep it as it is. Will they get a nasty surprise one day keeping the snapshot?
What would happen if you run the VM with a snapshot?
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Does this mean that snapshot disk will grow until it reaches the size of parent virtual disk over the period and then VM will stop?
Yes VM will fail. If it does not fail before, because of too many snapshots, not enough storage, or gets corrupted - pick one of the above!
Snapshots are designed for use as a temporary solution, really to allow backups to operate (poorly!), and Snapshots have been VMware's VMs Achilles heel, since the damn things were invented!
Experts Exchange gets a snapshot question issue weekly.... and our service desk daily, they are the most mis-understood VMware function, the next is VMware Converter P2V, followed by vCPUs!
ASKER
Thanks, Andrew, it is a good article, will forward the link to the Tech to read it.
They are playing Snapshot Russian Roulette!
Ticking Time Bomb, and it's only going to end one way - BAD
Ticking Time Bomb, and it's only going to end one way - BAD
ASKER
I forwarded your link. It is a great article.
thanks for your kind words.
I concur with Andrew: from our experience, the longer you keep a snapshot, the bigger the chance it will go wrong.
How does your client perform backups and why does the application fail if they do the backup? Does this mean they take no backups at all? One thing is for sure: snapshots are not backups.
How does your client perform backups and why does the application fail if they do the backup? Does this mean they take no backups at all? One thing is for sure: snapshots are not backups.
The main purpose of snapshot is to keep the OS safe from any unexpected damage.
Having said that you require snapshot , when you upgrading or patching your OS and you don't know what would be the result after that.
If the VM works find and application running as expected, delete the snapshot. If the VM is not running find revert it.
Having said that you require snapshot , when you upgrading or patching your OS and you don't know what would be the result after that.
If the VM works find and application running as expected, delete the snapshot. If the VM is not running find revert it.
ASKER
Snapshots can only be the same size as the parent virtual disk.[/b]
Does this mean that snapshot disk will grow until it reaches the size of parent virtual disk over the period and then VM will stop?