[lug] Reliable SATA server?

[Rob Nagler]

Over the years we've struggled to find a reliable SATA server for our
backups.  I have tried numerous versions of SATA computers, and they
all seem to fail under our loads, always.  The failure is usually in
the form of the computer hanging in such a bad state that it requires
a power cycle.

We do have a fairly stable server these days, but now I'm finding the
disk slots are failing -- along with the disks.  The server isn't that
old, but it has been relatively reliable (only the occasional hang).

I've attached a vmstat when the server is busy.  I can't do much on
the server at this time, e.g. tab completion of a command takes a few
seconds.  This is very different from a benchmark load so the numbers
are deceptive.

At this stage, I'm tempted to bite the bullet and go with SAS.  We
have SCSI3 machines running with heavy (but dissimilar) loads without
a problem.

I've asked this question on this list before, and not gotten a
satisfactory answer.  Nobody seems to run the same type of loads that
we do, and all their servers run just fine.  However, if you do have
experience with non-sequential writing of large amounts of data to
on a SATA server, please let me know. 

Thanks,
Rob

# vmstat 1
procs -----------memory---------- ---swap-- -----io---- --system-- -----cpu------
 r  b   swpd   free   buff  cache   si   so    bi    bo   in   cs us sy id wa st
 0  2    144  15672 328852 826992    0    0   300   184    9    3  2  1 91  6  0
 0  2    144  16136 328436 827052    0    0  3684     0 1544 1361  3  2 55 39  0
 0  2    144  19764 326164 826964    0    0 10948     0 1270 1253 10  2 52 37  0
 2  1    144  26640 321224 826268    0    0 27828  2948 1295 2364 21  3 50 26  0
 0  2    144  26504 320472 827268    0    0  5832     0 1375 1150 10  1 54 35  0
 0  3    144  29356 319048 826360    0    0  4688   784 1371  984 13  2 52 33  0
 0  3    144  29232 319048 826528    0    0    32  5624 1114   90  0  0 62 37  0
 0  2    144  29232 319048 826508    0    0     8   748 1119   72  0  0 54 46  0
 0  3    144  29232 319052 826532    0    0     8    36 1094   56  0  0 26 74  0
 0  2    144  29608 318708 826432    0    0  3244     4 1446 1138  3  2 52 43  0
 0  2    144  29884 318204 826952    0    0  2344  1000 1294  656  2  1 55 42  0
 1  2    144  32428 316516 826648    0    0  6388     0 1167  732 10  2 49 40  0
 1  2    144  35916 314220 825756    0    0  7476     0 1205  837 11  2 49 38  0
 0  2    144  37940 312616 825584    0    0  6484     0 1228  835 10  2 49 40  0
 0  2    144  39108 311712 825816    0    0  4184 14048 1235  553  5  1 50 44  0
 0  3    144  39428 310848 826544    0    0  4528  4956 1333  939  6  2 53 40  0
 0  3    144  39428 310852 826676    0    0     8   784 1131   80  0  0 51 49  0
 0  2    144  39428 310852 826644    0    0     8   468 1099   78  0  0 50 50  0
 0  2    144  40328 310620 825876    0    0   912     0 1338  694  0  0 52 48  0
 0  2    144  39600 310476 826804    0    0  3092   104 1492 1285  1  2 60 37  0
 0  2    144  40972 309896 826492    0    0  3636  1052 1312  806  3  1 54 42  0