[mythtv-users] MythTV as a Gift (Hardware Recommendations)
R. G. Newbury
newbury at mandamus.org
Wed Jan 23 16:31:20 UTC 2008
Brian Phillips wrote:
> Bill Omer wrote:
>> Actually, there is one more thing. What about a hard drive to load
>> the OS and run the database off of? I would recommend not running
>> the system and db off the same partition for storage.
> Why? I am pretty new at this mythtv thing and my playback (livetv or
> recordings) are sluggish when the db is being updated or queried
> (mythfilldatabase, program guide, mythweb listings, etc). I always thought
> it was the processor bottleneck (p3 550).
> Could it be that my hard drive is the bottleneck? Or are you recommending
> separate partitions just to preserve data integrity (ease of backups,
> rebuilds, etc) ?
> I have separate partitions for the db and storage directories as you
> recommend, but they share a physical disk drive and I was wondering if I'd
> get better performance splitting them across separate physical disks.
You might want to search the archive at gossamer threads for more
detail, as this has gone by before now.
Basically, the idea is that the OS is entirely separated from the data
store. The only thing stored on the OS disk, generally, will be the
mythconverg database (and it could be set to be stored elsewhere).
The video data storage is entirely different. It may be a group of disks
as a storage group, or a RAID array to prevent data loss.
The OS disk can be small, and could even be a ram disk, or solid state
setup. It can be tuned to handle many small files. The data disks can be
tuned, conversely for few and large files (Check the -m switch to
mkfs.ext2 for example, or mounting the data disks with noatime, and
nodiratime switches in fstab (which removes a write-to-disk requirement).
I'm running with a 13Gb OS disk and 120 and 250 Gb disks as 2 storage
group entries. I backup the mythconverg database and a number of my
scripts which live in /usr/local/sbin by cron early every morning, to
/video2. I figure it would take about 2 hours of operator time, and
4hours total (downloads and compiling) to do a bare metal reinstall
without data loss.
If you are on one spindle, an OS disaster or a hardware failure can
result in a complete data loss.
Tux says: "Be regular. Eat cron flakes."
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