On 16/10/18 21:46, Shaun Glass wrote:
Good Day,
We have some servers that that we have setup RAID 1 with mdadm. The
layout is having one disk in one VMWare Datastore and the other in
another VMWare Datastore. These are RHEL 7 Servers. LVM With EXT4
Filesystems.
Now they seem to function perfectly well without too much performance
impact until we run backups in the evening. Here we see backups
basically taking 5 times as long to complete as they normally would.
We use TSM for backups and it is typically flat file backups.
Please note these Datastores are in different DC's with a big network
link between. Since performance during the day is perfectly fine, we
are a bit lost as to why backups are taking so long.
Any suggestions ?
Most likely this is a latency issue between the two sites (not
bandwidth)... You would need to examine what technology you are using to
make that remote disk look like a local disk for mdadm. Also, did you
give mdadm a write-mostly flag for this "remote" disk? What other config
have you done (or not done)?
In fact, is it the live load that has this RAID1 or the backup server?
What is the performance of the backup server/what is it's config like?
Regards,
Adam
