There is no problem. Even if there is still available RAM, the Linux Kernel will move memory pages which are hardly ever used into swap space. It’s good to swap out memory pages that have been inactive for a while, keeping often-used data in cache; this is the desired situation of the Kernel. You can … Read more
It is possible that you do not generate enough IOPS for this to really kick-in. Have a look here on how to change the setting from default 1’000 IOPS to a smaller value. (This is symmetrix specific, but you can do the same for the VMWare Round Robin Provider) I’m however not yet convinced if … Read more
It is my understanding that ESXI snapshot removal can (and usually does) take a long time. Before the snapshot can be removed the changes from the old snapshot need to be written to the next snapshot in order. I was taught to always delete snapshots from oldest to most recent to help this process run … Read more
NAS Definitely not NAS for SQL Server. SMB/CIFS does not have adequate support for file locking to support a DBMS (at least it didn’t a few years ago, ca. 2002-2003). Note that NFS does and you can actually do this with Oracle on an NFS server. However, SQL Server on a CIFS share is not … Read more
does iscsiadm -m session tell you what you want to know? (or I think iscsiadm -m session -P 3 might give more info)
Consider whether you really need hot failover. If you’re worrying about price at the level of an entry level SAN then consider whether you really have a business case for that recovery model. How expensive is your downtime for an outage? If the cost of an outage justifies the cost of a decent SAN, buy … Read more
Logs and data drives have different data access patterns that are in conflict with each other (at least in theory) when they share a drive. Log Writes Log access consists of a very large number of small sequential writes. Somewhat simplistically, DB logs are ring buffers containing a list of instructions to write data items … Read more
Enabling Jumbo Frames means allowing a larger Maximum Transmission Unit (MTU), usually by setting the MTU to 9000. To verify this has worked you can use ping in windows with the -l flag to set the packet size, and the -f flag to set Don’t Fragment flag in the packet. ping my.test.host -f -l 8972 … Read more
I’m not familiar with VMWare, but I do use Xenserver and I have used Hyper-V (R2). With my current Xenserver configuration I have: 8 Dell Poweredge 29xx servers 2 Dell Powerconnect 6248 switches 2 Dell MD3000i SAN (iSCSI) I have setup my switches in a multipath configuration and optimized for iSCSI by: Separating my switches … Read more
You need to activate a volume group after you attached it. To activate all the inactive volumes on the system you would use a command like vgchange -a y.