[Linux-cluster] Cluster with shared storage on low budget
gordan at bobich.net
Tue Feb 15 16:17:03 UTC 2011
Jeff Sturm wrote:
>> -----Original Message-----
>> From: linux-cluster-bounces at redhat.com
> [mailto:linux-cluster-bounces at redhat.com]
>> On Behalf Of Gordan Bobic
>> Sent: Tuesday, February 15, 2011 7:05 AM
>> Volume resizing is, IMO, over-rated and unnecessary in most cases,
> except where data
>> growth is quite mind-boggling (in which case you won't be using MySQL
> We actually resize volumes often. Some of our storage volumes have 30
> LUNs or more. We have so many because we've virtualized most of our
> infrastructure, and some of the hosts are single-purpose hosts.
> We don't want to allocate too more storage in advance, simply because
> it's easier to grow than to shrink. Stop the host, grow the volume,
> e2fsck/resize2fs, start up and go. Much nicer than increasing disk
> capacity on physical hosts.
Seems labour and downtime intensive to me. Maybe I'm just used to
environments where that is an unacceptable tradeoff vs. £40/TB for storage.
Not to mention that it makes you totally reliant on SAN level
redundancy, which I also generally deem unacceptable except on very high
end SANs that have mirroring features.
Additionally, considering you can self-build a multi-TB iSCSI SAN for a
few hundred £/$/€ which will have volume growing ability (use sparse
files for iSCSI volumes and write a byte to a greater offset), I cannot
really see any justification whatsoever for using LVM with SAN based
> Haven't tried DRBD yet but I'm really tempted... it sounds like it has
> come a long way since its modest beginnings.
Not sure how far back you are talking about but I have been using it in
production in both active-active and active-passive configurations since
at least 2007 with no problems. From the usage point of view, the
changes have been negligible.
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